# To all the Incan haters



## wrathothebunny (Jun 18, 2007)

Ok, I just want to clear this up once and for all - quality of light matters! Have you guys ever heard of the 4 C's of diamonds: cut, color, clarity, and carat weight? The first 3 address quality, and the last addresses quantity. Sometimes, one gets the impression that the only thing that matters to the LED fanatics on these forums is quantity - meaning lumens and runtime. Lumens and runtime have NOTHING to do with the QUALITY of the beam, though everything to do with the QUANTITY of the beam. Both, of course, are important. So......let me remind you of some factors that influence beam quality, and why they matter.

*Beam Quantity*:

Lumens
Runtime
*
Beam Quality*:

Beam Spectrum (Color Temp, Color Rendering Index, and overall pattern of wavelengths emitted)
Beam Shape (Focus, Hot-Spot, Spill, Throw, Artifacts, etc.)
Temporal Qualities (How the quality of the light varies over the runtime of the lamp)


Now, to hear a lot of the LED fanatics talk, it sounds like they mostly focus on the quantity of light, not the quality. However, even when they do talk about the quality of light, it usually is in reference to the shape of the beam - i.e. spill, throw, etc. of the beam, and not the quality of the beam spectrum itself.

*Why the Beam Spectrum matters:*

Primarily, beam spectrum matters because we live in a world of color, and different colors absorb, refract, and reflect back different wavelengths of light differently. So, different wavelengths of light emitted by your flashlight will react differently with your environment, thus affecting how you perceive the colors of your environment - often in ways that affect your visual acuity and impacts perceptions of contrast and depth - in addition to just plain color accuracy.

Given how central this spectral quality of light is to our ability to visually perceive the environment around us, some very smart persons came up with the metric of the Color Rendering Index - or CRI. The CRI is a scale from 0 to 100, with 100 representing a broad, full representation of all of the wavelengths in the visual spectrum.

The light emitted from the Sun possesses this characteristic, and is rated at a CRI of 100. Most incandescent lights, also, produce a full spectrum of visual light, thus also rating at a CRI of 98 to 100.

Even the best white LEDs, however, only achieve CRIs of 80-82. The practical difference between 80-82 and 98-100 are huge. When you look at the spectral distribution of white LEDs, you see the reason for the lower CRI rating, they are almost completely deficient in the red/orange end of the spectrum, with a spike, instead, in the blue end and a substantial hump in the green and yellow portion.

What does this mean in real life? Well, outdoors, organic colors have a substantial representation in the red/orange end of the spectrum (think dirt, for instance), and the near total lack of this light in white LEDs renders these organic elements very poorly. When I walk my dog in the park with my Fenix P3D LED torch, the ground looks washed out, with low contrast, almost flat and nonexistent depth, and overall I feel that I am left with a poor visual acuity in perceiving my surroundings. When I render that same park with an incan, the ground suddenly takes on contrast and depth, the difference between the dirt and each blade of grass jumps out at me. In general, it is a much more pleasing and visually advantageous experience.

But, quantity of light matters too, so which light do I use to walk my dog? The Fenix P3D, because I don't have to change the batteries near as often. However, I would be fooling myself if I believed that an Incan wouldn't render the environment better - and for hiking on a trail where roots, rocks, and branches and they like can jump out at me, I guarantee you I will have an incan with me in addition to my long runtime LED.

So, to all you Incan haters out there, stop with all the "Incan is dead," or "I see no point to use (such an such an incan) when there is (such an such a "better" LED)," etc. I don't want to hear it. It is ignorant. And I hope after reading this post you can see why the QUALITY of the light coming from your flashlight matters.


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## Uncle Bob (Jun 18, 2007)

Oooops! Now there's a definite shot over the bow!


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## DM51 (Jun 18, 2007)

I can tell just from the title of the thread that this one is going to run. Now to read the original post and see what it says.


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## GreySave (Jun 18, 2007)

Wow. I mean....I agree with the technical and practical discussion and even the conclusion that there is room and a need for both types of lighting dependent upon the application. I personally use both LEDs and incans myself. But wow. This ought to be as interesting as the SureFire debates.....


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## Carpenter (Jun 18, 2007)

/me pulls up a seat next to Greysave


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## fod (Jun 18, 2007)

Interesting.

I, too have found that (White) LEDs tend to "bleach" out colors. But for the most part, it is (at least for myself) a reasonable trade off.

Edit: also getting relatively inexpensise colors in LED tuned for certain tasks is a great boon.
(E.G. Red LEDs for hunting night crawlers, and maintaining night vision) AFAIK, icans can only do this trick with filters...


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## CandlePowerForumsUser (Jun 18, 2007)

Thanks alot for this post. I'm going to have to get another E2E to replace the one my brother took because he liked it so much. :thumbsup:


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## Patriot (Jun 18, 2007)

Can we have a show of hand out there for people who actually "hate" incans? I guess that I don't usually here people say that. Like bunny, they usually have a reason that they prefer LEDs for certain tasks though. I love incans as 2nd lights, but not as my primary because of their runtime. I frequently need a light to run serveral hours at a time.


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## Reid (Jun 18, 2007)

> Even the best white LEDs, however, only achieve CRIs of 80-82.
> The practical difference between 80-82 and 98-100 are huge.


Perhaps it's a matter of future development?

Q: in the example of say, the humble, multiple-emitter flashlight for floodlighting purposes, 
does the CRI improve (somewhat, at least) with the addition of orange/red LEDs?


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## wrathothebunny (Jun 18, 2007)

Yes, future developments should improve the CRIs of LEDs. The CRI figures I just quoted for LEDs, by the way, are quite generous. Most white LEDs are actually a blue LED coated with a yellow phosphor - and these typically have CRIs in the 70-75 range. Better white LEDs coat multiple phosphors over a blue LED. The new Crees can achieve CRIs of 80, but my understanding is that this is only in the warmer color-temp chips, and some lumens/watt efficiency is sacrificed to achieve this.

Multiple emitter LEDs could address this problem, I know that Philips is working on what looks like a red-green-blue multi-die LED that can be used for accent lighting with high CRI.


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## WadeF (Jun 18, 2007)

I certainly enjoy the advantages the LED lights offer, but you speak the truth, their main fault right now is the way they render colors. I know I have peeked in on my kids while they are sleeping to make sure all is well, and when I light them up with my Fenix P1D-CE they look DEAD!  The first time they were illuminated with my P1D-CE I was a bit shocked as their flesh looked blueish and their lips purple/blue, as the LED lacked the red/orange to accurately render their flesh color. I quickly realized it was the LED light making them look this way and I had to watch to make sure there was a little movement from them breathing.  

It has been a lot of fun watching LED's advance and I hope the next big breakthrough is a higher CRI.


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## fod (Jun 18, 2007)

oh, and another thought...I don't hate incans, but the sodium vapor lights I can despise...the color rendition really are terrible, but they have trade offs that make the worthy of use in some areas...


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## OceanView (Jun 18, 2007)

Patriot36 said:


> Can we have a show of hand out there for people who actually "hate" incans? I guess that I don't usually here people say that.


I was thinking the same thing. I can't recall any recent post where someone really _hated_ incans. From time to time, you'll hear something, "After trying this new X LED light, I'll never go back to an incan" type statements, but that's rarely a put-down of incans. It's just that the LED flashlight (the flashlight, not necessarily just the light that comes out the front end) suits this person better than the typical incan, whether it's the lumens, runtime, no need to buy another bulb, etc.

There was a thread a while ago titled something like, "Who went from incans to LED and back again?" There were plenty of people who did just that, and for them, they realized that certain qualities of incans turned out to be very important to them, notably the spectral quality. And for those that never went back to incans, well, I guess LED lights fulfill their needs better than an incan.


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## Reid (Jun 18, 2007)

wrathothebunny said:


> Multiple emitter LEDs could address this problem, I know that Philips is working on what looks like a red-green-blue multi-die LED that can be used for accent lighting with high CRI.


Thinking about this now for the first time, yes, a tricolor set of LEDs must surely be the complete answer,
witness the tricolor LED monitor in front of our very eyes.

But, as for the focused, single emitter "throw" LED lamp? the challenges are as you say.

So, for today, for starting along this clearer-vision path, 
when walking the dog or walking in woods, 
it would be excellent to get incandescent quality floodlight, along with LED battery economy.

Couldn't this be done today, cheaply? 
China, are you reading?


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## Empath (Jun 18, 2007)

Having such a skill at making a point, it seems a shame to lose it through a lack of people skills.

Members that have a preference for, or even an exuberance toward a choice not your own aren't "fanatics" or "haters".

I cherish both those that love the LED and icans. Their exuberance has given huge improvements in lighting technology in a relatively short period of time.


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## wrathothebunny (Jun 18, 2007)

I singled no person out as a "hater" or a "fanatic." Also, the term "haters" in its common usage does not necessarily mean someone who hates. It can mean someone who disapproves or is opposed to something. The term "fanatics," I intended to use in such a manner as you call someone a sports "fanatic," rather than its more sharply negative meaning, as in religious "fanatic." This post was not meant to offend, just generate stimulating debate.

[Edit] To address Bogus1's later post, yes the "hater" bit was meant to be tongue-in-cheek and not meant to be taken overly seriously.


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## knot (Jun 18, 2007)

When I'm out in the dark, I don't care about colors. I want quantity of light in a small form. I'm not taking photographs of the landscape and I'm not stopping to smell the roses. I'm going from point A to point B in a well lit radius. However, there is a time and place for every light, including my Sam's HID.


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## Bogus1 (Jun 18, 2007)

Very nice post on the facts wrath! I would have to assume (and hope) the "hater" aspect of the thread is tongue in cheek and intended to keep a thread lively. Let's try not to get stodgy here and I can only hope it's obvious there are different tools for different jobs and that this fact was not overlooked by wrath in an effort to have fun. You aren't going to take a car on a bike path, but both will get you somewhere. 

We've had similar threads before but you put this one very well. I've even been able to 'cruise' forests at night evaluating large trees for health with an incan. Even a clustered LED light just as bright as an incan serves virtually no purpose in a natural setting where 'what it is' you are looking at matters.

It looks to me that AW's incan driver might address some of the gap of quantity which I find exciting. Of course the incan still won’t be as durable, however another advantage incan has is that you have a point source with more lumens on tap and can more readily create throw and still have flood as well. With LEDs you can have a multi array but are still lacking in throw, or you can have throw without flood. I think once we have an application of curved lenses on multi LEDs then perhaps this will change in favor of the LEDs. Of course also once LEDs become even more efficient we will have even more “quantity”.

I see this debate as similar to what happened with CDs and analogue sound. Forever the CDs were ultimately superior in convenience, portability, and durability compared to vinyl or even tape. However to this day they sound like dung. Our technology still hasn't allowed dithering down to the 16 bit format that sounds real. Unfortunately we rode technology all for the same limited results so now we have data so tiny you couldn't hold it in your hand with ipod data and MP3s. The problem is it keeps sounding worse! I would have preferred we used our technological advances instead to create real sound. This could be done with digital technology (and has been) but instead of just going smaller we would need to have better quality. At what point does it become nonsense to have more junk? When does quality and not just quantity begin to matter? It matters all the time! That's how I see this scenario. Incans simply produce light that looks more like, well natural light, and thus is a better tool for seeing if you ignore the form, just as vinyl still is superior if you ignore the various flaws in the medium. We are not cyborgs (yet) and we evolved to see in natural light.

The point is to pick the tools for the purpose and to keep an eye on the prize. That is to have an efficient LED with a proper visual spectrum. Those who prefer the ‘cooler’ tints are off base in this regard, unless they are not using the lights in nature or only seek white walls. Perhaps there is less concern about spectrum if you are only using it indoors or in a city where there is ambient light. I still think incans render three dimensional and spectral aspects better in all environments. ‘What color exactly was that car by way?’ ‘Don’t trip on the stairs’ etc.


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## sysadmn (Jun 18, 2007)

Not a hater, really! Different tools for different jobs! Part of the art of engineering is deciding which variables to optimize, and which to ignore. The flip side of this topic could be "To all the Battery Burners"  Is color of light more important than runtime? Absolute quantity of light, or having multi-levels?

Since everyone denies being a hater, maybe we can have an interesting, rational discussion 

Here's my contribution:
*Color Rendering Properties of LED Light Sources (pdf).*

Researchers found experiment subjects preferred LED-based lighting to halogen and incandescent of overall color, but disliked phosphor white LED for flesh tones. Also, the study showed that CRI does not predict color preferences. 

Here's the killer line for me: "The expectation is that CRI indicates the extent of the color rendering properties of a light source. However, in reality the CRI of a light source is a measure of the degree to which the perceived object colors illuminated by a test source conform to those of the same object illuminated by a standard source such as an incandescent light source."

I don't disagree with those who find _some_ incan light preferable to _some_ LED light in _some_ situations. It's just not clear that the CRI is the right club to use to beat on LEDs.

PS - the seminal work on CRI deficiency seems to be van Trigt, but I do not have access to the paper. At $25 for 24 hours to read the pdf, I'm not that curious


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## wrathothebunny (Jun 18, 2007)

CRI is not a subjective quality for visual acuity. Higher CRI = Higher Visual Acuity. In terms of how "pleasing" a light might look to a person, then yes, some people like lights with lower CRIs to lights with higher CRIs.

In my opinion, however, this preference is usually for the differences in color temperature, rather than the CRI itself. An example of this would be that many people prefer the lower CRI "cool white" compact fluorescent bulbs to their higher color temp "daylight" full-spectrum fluorescents, and often to their lower color temp incandescents.

This has much more to do with color temp than CRI, and absolutely nothing to do with visual acuity as it pertains to picking details out in your environment.

[Edit] After having read through your posted PDF, my suspicions have been confirmed. The subjects' preferences related almost entirely to color temperature with about 4K color temp being most preferred, under 3K being least preferred, and around 5K ranking in the middle. Again, this post is about what light better illuminates the environment to bring out detail, contrast, depth, and generally provides for better visual acuity. Not which light seems more "pleasant" in indoor tests.


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## mchlwise (Jun 18, 2007)

Call me a hater if you wish, but I much prefer the QUALITY of light from my LEDs over any incan, including my Surefire. 

I find quantity, quality, and spectrum of the light from my LEDs are all superior to an incan. 

As has been stated, though, the assessment of whether one is better than the other is subjective to the user, and overwhelmingly determined by preference. 

Continuing with the original diamond analogy: usually flouresence is not a desireable quality in a diamond - however, there are buyers who seek out flourscent diamonds, because that's their preference. 

I believe that's where the analogy stops, and otherwise it falls flat. There is no "governening" body to determine and quantitatively judge or "rate" the particular light coming from a flashlight. That is up to the individual and their preference, as the characteristics are not "better" or "worse" than others as they are with a diamond - they're just different. 

You prefer incandescents. Fine. You can have em. :nana:

But to make a post inferring that incandescent light is "better", and that those who prefer LEDs don't know quality and don't know what they're talking about and that they would realize the folly of their ways once you educate them is pretty arrogant. :shakehead


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## sysadmn (Jun 18, 2007)

Reid said:


> Thinking about this now for the first time, yes, a tricolor set of LEDs must surely be the complete answer,
> witness the tricolor LED monitor in front of our very eyes.
> 
> But, as for the focused, single emitter "throw" LED lamp? the challenges are as you say.
> ...


 
I recall seeing single emitter optics (_pdf_) that are (supposedly) optimized for full color mixing. This (_pdf_) seven cell optic claims complete mixing at 100mm from the fixture. MR11 optics have 50mm diameters, which is roughly Maglite C/D size. Unfortunately, led-spot has a 3 piece minimum, plus shipping. If you want to try 3 beam angles, it'll be 9 optics at ~$40 plus shipping.


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## Windscale (Jun 18, 2007)

I don't hate incands at all. They were all over the place before we had LEDs and we lived happily with them for years then. I still have many hidden in the drawers including Tec 40s, Scorpion, 6Ps, UKE2L, various Petzl headlamps etc. and the Mags to name but a few. But they did suck up batteries. Rechargeable AAs were barely up to 1600mah and there weren't R123As then. The game was expensive. All right, we afforded it. But the idea of having to carry tons of spare batts on each hike was not a good idea. Not to mention the adverse effects to the environment when we just chucked the dead batts away. The incands had to retire. But if one day batteries can improve so much that they can run the incand lights for much longer periods then the winds may change again. Since deciding to go 100% rechargeables, I don't see my incands making a come back beyond being switched on just to test if they are still working and to be viewed nostalgically when one brings up memories of places where these lights have been to. Sad but true. And one day the same will happen to our present LEDs too!


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## wrathothebunny (Jun 18, 2007)

Mchlwise,

I'm sorry to disagree with you, but CRI is not a "subjective" quality. I suspect you like your LED lights better because they are "whiter" than your incans. You might also like the beam shape better. I am not disputing the color temp or beamshape advantages that LED lights might have for you. Please, try to be more discriminating than just lumping all the visual phenomenon that's going on with your light into one subjective "quality." I guarantee you that if your LED light maintained the same color temperature and beamshape, but also emitted more full-spectrum light, you would find it a positive.

Higher CRI means higher visual acuity in visual perception. It is not a subjective phenomenon, it relates to how our eyes are built, how our visual processing centers work in our brain, and how this all interacts with the colors typically found in our environment - particularly outdoors. You might find one light more pleasing than the other, subjectively. But incans will render detail, contrast, and depth better - objectively. I don't know how I can make that any more clear.


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## yellow (Jun 18, 2007)

Sorry to type, but its still the usual BS 
Great and well thought out arguments, I really like to read and reflect over (even when I am switched to led-lights) 
but nothing more.

In regard to the other Tread (Fenix to E2):
*take both lights outdoors, switch them on both, arrange them side by side and take a pic with the cam on auto 
should give an instant comparison *

but, please, dont do the usual thing: comparing an ROP with a keychain led-light.
Mabe I find time to do a 6P LA <-> Cree led shot within the next days
PS, in regard to the last post, not submitted while I typed: of course a full spectrum led would be great!


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## Daniel_sk (Jun 18, 2007)

wrathothebunny said:


> Mchlwise,
> Higher CRI means higher visual acuity in visual perception. It is not a subjective phenomenon, it relates to how our eyes are built, how our visual processing centers work in our brain, and how this all interacts with the colors typically found in our environment - particularly outdoors. You might find one light more pleasing than the other, subjectively. But incans will render detail, contrast, and depth better - objectively. I don't know how I can make that any more clear.


That is so true - and you are right on the outdoors, when I take my LED headlamp (tikka xp, luxeon with pure white color) for hiking and shine into thick bushes arround me- then it creates a "white wall",branches that are close and branches that are further away look like in the same distance. This is the worst enviroment for LED, when there are "semi-transparent" objects arround you (like bushes and trees), most of the white is then reflected back to you, it's so bad that I stopped using the tikka (quite powerful on boost mode!) for such purposes (looking into the distance). I have a new SF A2, I am going to do a little comparision next time in the woods...


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## yellow (Jun 18, 2007)

man, a Tikka, and? 

Thats exactly what I mean:
Comparing a much more powerful incan with a low output Led (and in this case made for flood)
What if I tell You my car headlights are brighter than the A2? Is the A2 not good because of this? 
No, its the best incan with its regulation. The comparison is simply not fair.

Get Yourself an "ususal" incan headlight. Is this better than a similar sized and same time running led-light? Does it offer a better beam quality (think of the Petzls for example)
btw: even with headlamps the Tikka is not the best of the breed, maybe in the middle

*again: take pics!*


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## TITAN1833 (Jun 18, 2007)

I use both incan and led.but at this moment in time i hate my only incan.you see we had a power cut one evening,grabbing the nearest light..my ultrafire wf500 i went to investigate and i dropped the damn thing right onto my toes:green:so this is a sore subject at the moment.it weighs 364grms it landed strike bezel first.


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## Daniel_sk (Jun 18, 2007)

yellow said:


> man, a Tikka, and?
> 
> Thats exactly what I mean:
> *Comparing a much more powerful incan with a low output Led.*
> ...


 
I am not comparing the tikka xp to A2, I just said that LEDs are generally not good for such enviroments. It doesn't matter if it's 10 or 100 LED lumens. I have the Tikka XP, not Tikka, it's very bright in boost mode (quickbeam's review, the boost mode will overdrive the Luxeon, 20 seconds and thermal sensor will shut the light off), besides I have a Fenix L1D CE, and it's same. I will take the pictures as soon as possible (but my camera has only automatic mode - I hope it will work...).


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## knot (Jun 18, 2007)

If HID CRI = 65 - LED CRI = 70 - Incan = 90+

They say better color and contrast?: http://video.google.com/videoplay?d...176&start=0&num=10&so=0&type=search&plindex=0


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## TOOCOOL (Jun 18, 2007)

They still make incandescents ?


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## QuinnK (Jun 18, 2007)

TITAN1833 

**OUCH**

I bet that smarted just a bit...


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## wrathothebunny (Jun 18, 2007)

Knot,

The new ceramic metal halide HIDs can achieve CRIs in the 90s, or so I've heard.


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## TITAN1833 (Jun 18, 2007)

QuinnK said:


> TITAN1833
> 
> **OUCH**
> 
> I bet that smarted just a bit...


yeah the wf500 is ok though.i keep my photonfreedom with me now.LOL.


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## yellow (Jun 18, 2007)

Sorry Daniel, I got that post wrong,
You typed that You got the A2 later,
my bad


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## Daekar (Jun 18, 2007)

wrathothebunny said:


> Mchlwise,
> 
> I'm sorry to disagree with you, but CRI is not a "subjective" quality. I suspect you like your LED lights better because they are "whiter" than your incans. You might also like the beam shape better. I am not disputing the color temp or beamshape advantages that LED lights might have for you. Please, try to be more discriminating than just lumping all the visual phenomenon that's going on with your light into one subjective "quality." I guarantee you that if your LED light maintained the same color temperature and beamshape, but also emitted more full-spectrum light, you would find it a positive.
> 
> Higher CRI means higher visual acuity in visual perception. It is not a subjective phenomenon, it relates to how our eyes are built, how our visual processing centers work in our brain, and how this all interacts with the colors typically found in our environment - particularly outdoors. You might find one light more pleasing than the other, subjectively. But incans will render detail, contrast, and depth better - objectively. I don't know how I can make that any more clear.


 
I completely agree with you in that multiple wavelengths are a desirable quality in most light sources. However, in my experience, most incans have just as poor color rendering as LEDs... they just have it at the opposite end of the spectrum. Maybe high-dollar incans have better color rendering? The P60 bulb in the Surefires I've seen don't have it, so I'm betting it's not that common. 

Again, not disagreeing on principle, simply contesting the assertion that most incans are better for color rendering...


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## 2xTrinity (Jun 18, 2007)

> Higher CRI means higher visual acuity in visual perception. It is not a subjective phenomenon, it relates to how our eyes are built, how our visual processing centers work in our brain, and how this all interacts with the colors typically found in our environment - particularly outdoors. You might find one light more pleasing than the other, subjectively. But incans will render detail, contrast, and depth better - objectively. I don't know how I can make that any more clear.


while for the most part this is true, that is not always the case. CRI is actually a measure of how closely a light sources matches a blackbody radiator _at a particular color temperature_. The color temperature is an important factor. Consider the following two in a comparison: a long-life household incandescent lamp at 2600K, and a halogen lamp operating at 3200K. Both have CRI of 100 by definition as they are blackbody emitters, but the halogen at 3200K will provide better visual acuity and color rendering lumen-for-lumen. 

While the brain does have the ability to compensate by "white balancing" (particularly if CRI is high in all cases) I find that strongly-tinted light sources require more overall light in order to get the same acuity as a neutral source -- for example, if I need to sort socks that are all various shades of blue under a yellowish incandescent lighting, will take a lot more overall lumens for there to be enough blue component to get the job done than from a whiter halogen, or fluorescent light. I have actually recently replaced several 14W 2700K CFLs with 9W 3500K CFLs. Many have commented that the rooms actually look brighter now, even with fewer lumens





> Perhaps it's a matter of future development?
> 
> Q: in the example of say, the humble, multiple-emitter flashlight for floodlighting purposes,
> does the CRI improve (somewhat, at least) with the addition of orange/red LEDs?


Absolutely. for close-range outdoor use, the improvement is almost night and day. The biggest problem with phosphor LEDs is a lack of red. Actual red (rather than red/orange) is best for this, and it doesn't take much. If using Cree Emitters and Red Lux III emitters driven at the same wattage, I find that one red emitter will fill in the red deficiency for about 5 Crees. I'm considering building a multi-emitter maglite now, with a frosted UCL (to blend the colors, and soften the beam) in order to have a bright flood light that also has good runtime, especially for use as a "candle" in a power outage. The beam pattern looks uglier, but color rendering and depth perception improves. 

I know that at least prototypes of ~4000K LEDs with two-phoshpors, and over 95CRI have been made. If such an emitter as that were available to the general public, I believe that would be the "holy grail" of flashlight emitters. It would be very similar to natural moonlight in terms of spectrum.


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## wrathothebunny (Jun 18, 2007)

Daekar,

The higher color-temp xenons will render colors with more violet, blue, and green elements better, due to the presence of more photons in those wavelengths in the visual spectrum outputing from the xenon module. The new LumensFactory lamps, as well as the regulated output of the SureFire A2 do very well in this regard. Ideally, this would be recognized in a higher CRI rating (which is a very useful, though still rough metric for color rendering), but for very specific analysis of the color and contrast rendering properties of a light source, nothing beats looking at the actual spectral distribution.

[Edit] To 2xTrinity, I believe this addresses your post as well.


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## RustyKnee (Jun 18, 2007)

I hate all non LED lights especially my HID Boxer 24 and Mag85...they suck....actually no...i love them. I love LEDs too though, but wish they had better CRI.

I have been playing with adding red to a triple seoul setup

both pics were with the same white balance setting as well as being same manual settings....also...I am 30...although the items in the pic may not make it look that way hehe.

Both are with 3 P4s at 0.7Amp, two narrow khatods with frosting in front and 1 wide khatod with out frosting. The Red lux 3 was in the same wide kahtod type reflector running at 0.3Amps

Without Red

With Red

Stu


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## wrathothebunny (Jun 18, 2007)

RustyKnee,

That red mod looks fantastic! I think these photos clearly illustrate the contrast and depth issues I was talking about. You can also see, on the toy van, that the red stripe is almost completely invisible with the just the white LEDs, but once the red LED is added - POW, there it is. Great job RustyKnee :twothumbs


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## Blindasabat (Jun 18, 2007)

*To all the LED Lovers*

There are many facets to the practical side (application of current technology) of this debate. 

There are personal preferences in tint and color temperature for just play purposes (blue light that looks "cool" or high tech to some people), and the preference for more red tinted (warmer in MY definition) or greenish tints for out door use that work better off dirt or vegetation. I have stated several times before that LEDs still need to improve spectrum to be better light sources, but I still prefer them since I have been able to drop warmer (yellower to me) LED in some lights to make them give me better (to an acceptable extent) color and depth rendition outdoors.
I dropped an SV1H Lux 3 into a PT EOS and it works better than most LEDs of other tints. Not as good as a full spectrum Incan, but not bad at all, and is noticeable better than a lot of LEDs for hiking over rocks at night. I found this out when I happened to get a Nuwai Q3 with an SV1K in it and compared it to other LEDs outdoors.

Then there are the different spectrums of LEDs that are finding applications in science or law enforcement. I found it interesting that Pelican said the LAPD found cooler tints saw through window tinting more easily, so are using it for the LAPD light.

Then of course the efficiency differences. LEDs have made improvements here that Incans just can't keep up with.

The regulation of LEDs that incans seem to be missing out on for no good reason (aside from the SF A2 of course). This helps both efficiency and color of incans. The drop in incan efficiency with battery voltage drop is crying out for a simple PWM regulator like the A2 has.

And the fact that most common incans run badly on common Nimh's. The easiest and cheapest decent work around for non CPF'ers seems to be dropping 4 NiMh C cells in a 3D Mag with a 3 cell bulb, ...or a 3 cell bulb in a 4D now that I think of it (I have a 3d, not a 4D). 

People usually have to take ALL of these into consideration, weighing more heavily on the one(s) that concern them the most, in making a light purchase decision - IF they are informed enough to 

Notice I changed the subject line to be more positive.


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## BGater (Jun 18, 2007)

Man, everyone must have better eyes and better incans than I do. I have no problems with my LED lights, and prefer them. Im talking mostly about Lux's, Cree, SSC's, ect. All of the incans I have, have a dim **** yellow or golden color beam. I have several multi D Mags, many other D and C cell cheapo's, several 6 volt gell batteries with a rheostat running a 4volt bulb in a 5100 Wheat head (way bright in its day) and I would still choose my LED's. If I step outside and compare my 6D mag (stock incan bulb) to my L2Dce.....its a joke. The L2D puts out a huge amount of light, its not a spotlight, but it puts any of my incans to shame. My machine shed is a good 100' long by 60' wide. My L2D or even L1D will light it up inside well enough to see most everything. It impressive, my brother in law was amazed to say the least at the differance in light over my incans. Not to mention how many times I have dropped or bumped my incan and poof out goes the light bulb. Way more runtime, a wall of light, tiny form factor, no blown bulbs, ect, all make LEDs preferable to me. Incans have their uses and always will as has been stated above. But, for 90% of the people out there who just need light to see by and will enjoy great runtime and small size, LED's are the now and future. If your in a job, business, situation that needs incan light I think they will always be available and im glad they are. But for me, my last dollar was spent on an incan long ago.


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## Illum (Jun 18, 2007)




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## HarveyRich (Jun 18, 2007)

wrathothebunny: You make some excellent points. I don't deny that incans have a higher CRI which make it easier to distinguish features that you see. However, I agree with the posters who add the subjective element, which I think is very important for how you feel about the led. Many people love sitting indoors and reading by the yellowish light of the normal incan light bulb. I prefer the whiter light of some of the fluorescents for reading. This is a personal preference. I would agree that leds would be much nicer with a higher CRI index, but the yellowish incandescent light leaves me cold. Something inbetween the led and incan in color renditiion would work best for me.

Harvey


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## mchlwise (Jun 18, 2007)

wrathothebunny said:


> RustyKnee,
> 
> That red mod looks fantastic! I think these photos clearly illustrate the contrast and depth issues I was talking about. You can also see, on the toy van, that the red stripe is almost completely invisible with the just the white LEDs, but once the red LED is added - POW, there it is. Great job RustyKnee :twothumbs



It's funny, and actually points out very well how SUBJECTIVE this issue really is (no matter how much you try to show some kind of scientific proof that your opinion is right) - because I thought Rusty's post backed up my preference for LED. 

I preferred Rusty's non-red picture to the one with the red mod. Of course some things (like the red stripe on the van which is CLEARLY visible without the red led) will show better with the red added, but others will not. 

Look at the woodgrain, for example. There are greens and browns visible with the LED which are completely washed out in a sea of red, and the un-modded LED while certainly more green-shifted actually shows more of the natural colors of the wood than with the red. 

I use LED lights outside in my yard ALL the time to water the garden and flower beds at night, and I have NEVER had a problem with color rendition. In fact, I have frequently been impressed by how some of the colors of flowers and leaves etc. seem to pop in the light. 

Again... you can like incandescents all you want. You have every right to prefer them, and to believe they're better FOR YOU. But you keep coming across as an arrogant know-it-all-about-light-quality who is bound and determined to educate the ignorant led-loving masses. It appears that you believe that if you could just get us to understand your "proof" and obtain some of your "knowledge" on the subject, we would all change our minds. 

It's just not the case. :shakehead


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## Daniel_sk (Jun 18, 2007)

yellow said:


> Sorry Daniel, I got that post wrong,
> You typed that You got the A2 later,
> my bad


No problem . The last sentence about the A2 could had been written better (my english is not that good :green. I haven't tried the A2 in the outdoors yet (maybe this weekend, if I manage to pass the school exams :mecry.


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## jtr1962 (Jun 18, 2007)

I personally think the Cree WH bin comes about as close to natural sunlight as any artificial light source I've seen. Granted, there is still a deficiency in deep red, but by the same token incandescent has a deficiency in purple and blue. Even with this "deficiency", things just look more natural under a Cree than they do under the strongly yellow bias of an incandescent. As for the alleged superior depth perception sometimes attributed to incandescent, I suspect that has to do with beam artifacts. A perfectly smooth beam as is often present with LED lights does sometimes make things look "flat", but then so does a perfectly smooth incandescent beam. However, as a general rule incandescent beams usually tend to have some artifacts. Maybe some beam artifacts are actually a good thing (just not as many as a Maglight!)? Just a theory I have. Perhaps if more LED lights used optics, which are more efficient than reflectors but usually tend to have artifacts, the comparison might be fairer.

On another note, I wouldn't call myself an incandescent hater, but there are several things I definitely hate about them. First and foremost is the ridiculously short life. In order to get reasonable (~3500K) color temperature an incandescent filament needs to be driven to near the point of melting. This means a lifetime of at best 15 hours, often less than 5. Regardless of any other merits an incandescent may have that fact alone makes incandescent useless to me. I just can't afford to replace expensive bulbs on a regular basis. I totally gave up on having headlights on my bike for that reason alone until LEDs came along. Second is the heat they make. Third is their higher power consumption. I'll tolerate whatever shortcomings LEDs supposedly have (to my eyes LED actually seems better than incandescent in every way but maybe my eyes are atypical) in exchange for longer run time, far longer life, less heat, etc.

I could make a similar argument for interior general lighting. For me personally incandescents haven't even been on the radar in 25 years. Any supposedly CRI deficiencies in fluorescent lighting are more than compensated for by more like sunlight color temperature. Less heat plus much longer life, especially for the linear tubes, seals the deal for me. Advances in the last few years in linear tubes have only further made incandescent less viable.


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## RustyKnee (Jun 18, 2007)

mchlwise said:


> It's funny, and actually points out very well how SUBJECTIVE this issue really is (no matter how much you try to show some kind of scientific proof that your opinion is right) - because I thought Rusty's post backed up my preference for LED.
> 
> I preferred Rusty's non-red picture to the one with the red mod. Of course some things (like the red stripe on the van which is CLEARLY visible without the red led) will show better with the red added, but others will not.
> 
> ...



I agrre its horses for courses. But the wood effect on that book colour looks alot more like in life with the red, it is quite orangy. I have the luxury of seeing those opjects in daylight.

that really is a tiny amount of red added compared to the blue and yellow/green of the white leds. BA is green and brown with gold bits. with white only the greena dn browns merge. Its not so obvious in the pic due to him being quite shiney. with the red the browns are easier to see and have better cobntrast to the green.


the brake calipers on the kawasaki are orange and are more accurately depicted with the orange.

the wall to the right of the door is a kind of peach colour. looks more like in life with the red. The sony car stero box on the right pops out as its red and black. same goes for the thunder cats dvd box. the red pops out and the black shaded area reduces where the black and red are mixed.

the door is off white, slightly cream. it looks blue with just the white.

Look for the shadows on the door dure to different led position. you can see you much bluer the door is where the red is shaded. there is a shadow of BA above the van on the book.

And thank you wrath for independently coming up to the same conclusion as I did. Although if any one wants to argue that conclusuion feel free with constructive comments .


Stu


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## wrathothebunny (Jun 18, 2007)

Mchlwise,

I think you're just digging your own grave at this point. While I think the red is overdone and could stand to be toned down a bit, I think the pictures speak for themselves as to the better contrast and color rendering provided once the white LED spectrum is filled out on the red side.


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## AndyTiedye (Jun 18, 2007)

Incans can look nice and "white", but only if you overdrive them a lot.
Then they go  and leave you in the dark. :candle:

Otherwise you get this yellowish light that gets even yellower as the batteries die.

The future belongs to LEDs.


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## RustyKnee (Jun 18, 2007)

wrathothebunny said:


> Mchlwise,
> 
> I think you're just digging your own grave at this point. While I think the red is overdone and could stand to be toned down a bit, I think the pictures speak for themselves as to the better contrast and color rendering provided once the white LED spectrum is filled out on the red side.



the red augmentation was very slight. Its was hard to not make it turn pink even at low levels. i might try adding more green aswell at some point to see if it "genuinly whitens" it all up.

i think i was adding about 40ln or red to about 450 of white if i remember correctly from my calcs.

Stu


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## wrathothebunny (Jun 18, 2007)

To all of the posters who denigrate incan output for being so yellow as to render colors unnaturally, I would like to point out that while the color temp of sunlight at noon is about 5500K on a bright day, the color temp of sunlight at sunrise and sunset is about 3200K - of course, the CRI is always 100. SureFires, particularly when paired with LumensFactory ultra-high-pressure Xenon lamp assemblies, are able to produce color matching and even slightly exceeding this sunrise/sunset color temp level. So, I don't consider incan output to be "unnaturally yellow," provided you are using a good high-temp incan. If you're talking mag-lites, then yes, too yellow.


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## mchlwise (Jun 18, 2007)

wrathothebunny said:


> Mchlwise,
> 
> I think you're just digging your own grave at this point. While I think the red is overdone and could stand to be toned down a bit, I think the pictures speak for themselves as to the better contrast and color rendering provided once the white LED spectrum is filled out on the red side.



:shakehead :laughing: 

See, this is why this discussion is so senseless, and why I won't be participating in it anymore. 

You say I'm "digging my own grave" as if I'm going to be buried. I'll of course be dead, you'll be alive, and therefor you'll be the winner. 

You look at this issue and "right and wrong", "win or lose", "live or die." 

And that is exactly the problem. 

You have an opinion. That's fine. Nobody's going to attack or torture you to change it. But your opinion is just that. An OPINION. 

Others have opinions also, and they differ from yours. There's nothing wrong with that. 

But you can't see it that way. You can't accept that others can think differently than you. You must try to "PROVE" how someone's opinion is wrong. You have no respect for their right to have one, you only attack to try to bolster your position and demonstrate your... "rightness." 

Nothing constructive can come from such a position. 

You're not right. But I'm not wrong. We differ in opinions. 

Since you can't see that... I'm out.


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## 2xTrinity (Jun 18, 2007)

RustyKnee said:


> the red augmentation was very slight. Its was hard to not make it turn pink even at low levels. i might try adding more green aswell at some point to see if it "genuinly whitens" it all up.
> 
> i think i was adding about 40ln or red to about 450 of white if i remember correctly from my calcs.
> 
> Stu


Yeah, the amount of red that needs to be added to get a big improvement is slight. A red photon that I keep on my keychain is enough to "correct" my L0D-CE, which is a very very bright white flashlight by comparison. Also, one issue with this is color-mixing. If you repeated the shot using ceiling-bounce, rather than a direct beam, it would look a lot cleaner for all the naysayers out there.



> To all of the posters who denigrate incan output for being so yellow as to render colors unnaturally, I would like to point out that while the color temp of sunlight at noon is about 5500K on a bright day, the color temp of sunlight at sunrise and sunset is about 3200K - of course, the CRI is always 100. SureFires, particularly when paired with LumensFactory ultra-high-pressure Xenon lamp assemblies, are able to produce color matching and even slightly exceeding this sunrise/sunset color temp level. So, I don't consider incan output to be "unnaturally yellow," provided you are using a good high-temp incan. If you're talking mag-lites, then yes, too yellow.


This goes back to the point I mentioned about white-balancing. Provided the color rendering is high in all cases (100, in the case of the daylight at any hour) then the eyes can adjust to all different color temperatures, especially within that range seen during daytime (6000 - 3200K or so), outside the range though on either extreme, even with high CRI, a lot of detail is lost. 

In the case of hotwire flashlights that run over 3200k, those are a huge difference compared to crappy Mag Krypton bulbs. The difference between good and bad LEDs can be just as extreme though. For example, a lot of LEDs, such as the Cree WC bins are quite ugly, around 6500k with a slight bluish cast. The difference between that and say a Cree WH bin (5000k, slight yellow/green cast -- renders things like skin tones acceptably well) is just as extreme. IMO, the absolute ideal would be right in between the hotwire and the WH: (5000+3200)/2 = 4100K, but with 100CRI (The typical fluorescent lamp is 4100K, but only 75CRI, or even 60CRI for old T12s)



> As for the alleged superior depth perception sometimes attributed to incandescent, I suspect that has to do with beam artifacts. A perfectly smooth beam as is often present with LED lights does sometimes make things look "flat", but then so does a perfectly smooth incandescent beam. However, as a general rule incandescent beams usually tend to have some artifacts. Maybe some beam artifacts are actually a good thing (just not as many as a Maglight!)? Just a theory I have. Perhaps if more LED lights used optics, which are more efficient than reflectors but usually tend to have artifacts, the comparison might be fairer.


Incandescent beams are almost always more collimated than LEDs due to the fact that the filament is more concentrated than the die on an LED, and incans project light 360 degrees, so almost all of it hits a reflector with very spill. Most LED lights emit the majority of their light output as spill. Optics-based LED lights are closer to incan in terms of beam pattern, and they do provide depth perception than my reflector-based LEDs, as there is less spill lighting up dust particles etc. in the air. Also, bright spill can light up objects nearby and cause the pupils to adapt, making distant targets harder to see. 

My best LED light outdoors -- a Lumapower M1 with an aspheric lens -- is actually one of the worst for color in a ceiling bounce test, and it beats LED lights with much higher quality emitters:


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## wrathothebunny (Jun 18, 2007)

Mchlwise,

We live in a society today where the "freedom" of opinions has become the new freedom of speech. Of course you and everyone else is entitled to their opinions, and rightly so. But it does society no good when people say, "well, that's just my opinion" and leave it at that, without looking to facts to INFORM their opinions. Have you every heard of the phrases, "informed opinion" or "educated guess" or "working hypothesis?" It would be like, if you had an opinion, either for or against global warming, and you said to someone presenting you facts, "well, that's just my opinion, why do you have to assert that you are right?" - while not actually trying to look into the facts yourself and have a dialog where the truth may be better discerned. The wonderful thing about having a free and open society where individuals can express their views is it affords us the opportunity to get past just the opinions, and learn from each other in our journey toward KNOWLEDGE.


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## jtr1962 (Jun 18, 2007)

wrathothebunny said:


> To all of the posters who denigrate incan output for being so yellow as to render colors unnaturally, I would like to point out that while the color temp of sunlight at noon is about 5500K on a bright day, the color temp of sunlight at sunrise and sunset is about 3200K - of course, the CRI is always 100. SureFires, particularly when paired with LumensFactory ultra-high-pressure Xenon lamp assemblies, are able to produce color matching and even slightly exceeding this sunrise/sunset color temp level. So, I don't consider incan output to be "unnaturally yellow," provided you are using a good high-temp incan. If you're talking mag-lites, then yes, too yellow.


Sunrise/sunset is what percentage of the day? I won't argue that 3200K is necessarily "unnatural". It's just that our visual systems are best at dealing with the type of light usually present for most of the day. The autocolorbalance feature of our brains lets us compensate for some variation, of course, but it seems contrast/visual acuity is at its best in color temps around that of midday sunlight. And there's limits to how far the autocolorbalance works. I find with me personally 3500K is about the lowest color temp where I can sense a white point. Some of the better incandescents can seem "almost white" to me, but not quite.


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## wrathothebunny (Jun 18, 2007)

Actually, your point about how we have adapted to natural sunlight is more right than you know. In very bright light, the human visual system responds best to high color temp light. In dimmer light, lower color temp seems preferable. This would make sense from an evolutionary point of view, as noon sunlight is bright, and sunrise/sunset sunlight is dimmer.

That is why my super-premium 5900 K full-spectrum compact fluorescents look fine during the day lighting my home, but at night they look unnaturally ghosty. Most people prefer warmer lighting in their houses for this very reason, I believe, as indoor light is on orders of magnitude dimmer than noon sunlight. People don't generally like their high color temp "daylight" bulbs so much (in general, I know some do, but this is why the "cool white" and "warm white" CFLs are the most popular), but they have no problem with the high color temp sunlight coming through their windows (which is much higher intensity).

As typical flashlight use at night produces light levels closer to sunrise or sunset, low color temp should not be a problem. I think someone mentioned 4000 K color temp as ideal for flashlights, I would second that, but I don't see 3200-3300 K as being too yellow. Your preference for color temp might make a 3200 K incan too yellow, but that light will still more favorably interact with your visual system to provide you with FAR better visual acuity of your environment than a higher color temp LED with lower CRI, although you may prefer the "whiter" look.

To illustrate my above points, please refer to this figure of preferred color temperature for varying levels of light intensity. The yellow region is meant to represent the most ideal range of color temp per level of illumination.


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## jtr1962 (Jun 18, 2007)

wrathothebunny said:


> Most people prefer warmer lighting in their houses for this very reason, I believe, as indoor light is on orders of magnitude dimmer than noon sunlight.


Some truth to that as I like 5000K lighting at night, but I also light to levels much higher than most people do (my bedroom ceiling light is 4x32W T8s putting out roughly 10,500 lumens for a 110 ft² room, or roughly 1000 lux).



> Your preference for color temp might make a 3200K incan too yellow, but that light will still more favorably interact with your visual system to provide you with FAR better visual acuity of your environment than a higher color temp LED with lower CRI, although you may prefer the "whiter" look.


Well, I don't like LEDs which are too blue, either, but I do like the whiter look of LEDs. There may have initially been some novelty factor involved, but I have a definite cosmetic preference for them over incandescents, even if they do indeed give me lower visual acuity (something I have yet to test). For what it's worth, I have come to associate strongly blue-tinted LEDs with cheaply-made clone products, much as I have long associated the yellow tint of incandescents with cheap, "toy" flashlights, or quick to burn out household light bulbs. I guess summing it up, for me a pure white LED is something I equate with quality. Blue tinted LEDs, or yellow incandescents, I equate with low-cost, shoddy, disposible products. Probably not logical, but a subject like this is likely to be full of personal biases anyway.


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## Owen (Jun 18, 2007)

Incans are not "full spectrum light". They are also strongly tinted. Tint being a variation from white. Where they shine is in "color return"(for lack of a real term) when you factor in distance and environmental conditions that simultaneously wreck an LED's intensity and color rendition.
The relationship between colors is not subjective, but the conditions under which we use our lights, their individual tints, intensity, and beam characteristics certainly are. 
The same neutrally tinted LED that perfectly renders the colors of the clothes in my closet makes my back yard look like a lunar landscape except at close range. By the same token, my incans perform the opposite under similar conditions, lending much greater definition at longer range, and negatively affecting color balance up close.
One isn't necessarily better than the other, though due to my personal use I am a "incan lover".

I've been looking into upgraded headlights and foglights for my truck, and after searching and searching have found a surprising lack of consensus between multiple users of just a handful of different bulbs, though the discussions I've found have been pretty objective(mostly at tundrasolutions.com) as some users have included descriptions of their typical driving conditions and noted the performance of their bulbs without arguing the fact that their conclusions differ from someone else using an identical one. It's actually a bit confusing for a prospective buyer...

I'm as argumentative as anybody, but this incan vs. LED stuff is a moot point, IMO. Maybe one day we'll have a light source that works equally well for all uses, and obsoletes everything we use today, but that day isn't here yet.


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## adamr999 (Jun 18, 2007)

Incandescent lamps are much better suited for the medical field. Before becoming an engineer I was a EMT, and if you try to illuminate an IV site with an LED the vein will blend in with the light. Surgeons also need correct color rendition because of all the blood vessels they are trying to avoid. 

I like both LED's and incandescent lamps, but I don't prefer one over the other.


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## EV_007 (Jun 18, 2007)

Interesting thread. I've always maintained that incans, despite their battery sucking, "yellow" light, are the best choice for outdoor color rendition.

I love the LEDs for their smaller size, and longer battery life, but wouldn't use them solely for quick identification of subtle targets out in the wild. Trees, leaves and general "nature" stands out better than LEDs, but at the cost of runtime and bulb life of course.

I'm still an incan guy though.


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## wrathothebunny (Jun 18, 2007)

Owen said:


> Incans are not "full spectrum light". They are also strongly tinted. Tint being a variation from white.



So then you feel that the Sun at sunset/sunrise is not full spectrum then, as it's tinted warmer? You are confusing "full spectrum" with color temperature. You can have a full spectrum light tinted towards blue, with a CRI of 100, and you can have a full spectrum light tinted towards yellow, with a CRI of 100. You can also have a completely "neutral" tinted light, with a color temp in the range of 5000-5500 Kelvin, that is not full spectrum, with a CRI of 70 (hell, for the sake of argument you could have it at 1). Read through the earlier posts, there has been much information posted that covers all this.


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## mdocod (Jun 18, 2007)

OK wrath, you know I'm an incan guy. I agree that incandecent light sources provide a more vivid, realistic rendering of objects, especially nature stuff... but... here's the problem...

I go into a cave.. Lets say my headlamp is a Seoul modded 1W SL argo HP running on a 17670. That's 4-5 hours of regulated light on 1 17670 about 60+ torch lumens or so, on low, it's 20-30 hours runtime and the efficiency is even greater, providing about 20+ lumens..

Assuming I were going to go with incan to get a similar quantity of light, with 2 mode operation, and match the 4 hours runtime on high, and 20 hours on low. I would need to have 2 bulbs rather than 1 LED (a low power bulb and a high power bulb, since a high powered bulb under-driven to 1/3 the output would be horrendously inefficient and have a lousy CCT..) So.. to shoot for a similar range of output, I would need about a 5W high and 2W low bulb. In order to match the runtime, I would have to pack approximately 4 17670s instead of 1. And I would have to pack spare bulbs.

I have been tossing around the idea of designing a headlamp that could use a D26 style lamp, so I could run an HO-4 or ES-9 as a primary light while doing various tasks and adventure like caving, but would probably end up with battery packs consisting of 4 18650s in order to get runtime up high enough for headlamp type usage (~5 hours)..

So, in retrospect, the quantity in conjunction with efficiency in this circumstance, weighs so heavily in favor of modern LEDs, that it's very difficult to justify the use of incandecent regardless of the quality of the light.

There's no right or wrong here, only preference and opinion. Choosing the right tool for the job often requires trade-offs. In a few years, someone will be starting a thread titled "to all you led haters" and point to all the new wide spectrum LEDs available and the pointlessness of incandecent. Then they'll come out with a new synthesized filament material in conjunction with IRC technology in conjunction with some phosphor that can be introduced into fill gas of a lamp, and someone else will start a thread the other way around again, pointing to the new incandecent lamps making 100lm/w with a white points of 4500K and CRI of 100. Back and forth and back and forth...

Eventually. LEDs will close the CRI gap, we're already seeing multi-phosphor warmer LEDs doing this, and eventually, incandecent will close the efficiency gap. We've already seen 50-60lm/w demonstrated with IRC technology.


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## Patriot (Jun 18, 2007)

TITAN1833 said:


> I use both incan and led.but at this moment in time i hate my only incan.you see we had a power cut one evening,grabbing the nearest light..my ultrafire wf500 i went to investigate and i dropped the damn thing right onto my toes:green:so this is a sore subject at the moment.it weighs 364grms it landed strike bezel first.


 
Would you have prefered a 3 cell magLED? :mecry: Just kidding with ya. That would certainly hurt!


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## wrathothebunny (Jun 18, 2007)

Mdocod,

I think you may have misunderstood the message of my post (I apologize if that is not the case). I am not saying incans are better or even more preferable to LEDs. I did not post a LED vs. incan thread, though I understand it has been misunderstood to be that by some. I am trying to bring some perspective to the advantages of incandescents, the kinds of advantages that go into the cost-benefit equation that, on the other side, balances the efficiency advantages of LEDs. In some circumstances, the equation tips in favor of LEDs, in other circumstances, the equation tips in favor of incandescents. I know you stated that it is all a matter of opinion, that there is no right or wrong. I don't see it that way, I see it as an equation that incorporates objective factors in addition to the unique subjective experiences of the individual.

We live in a society today that values relativism and the all-mighty and immutable opinion. This is why democrats and republicans can never seem to get anywhere in their debates with each other, only throwing their opinions back and forth - not really sacrificing their "right" to their opinions for the greater good of allowing facts to shape their opinions, not just their own wills.

I prefer logic, empiricism, open debate, and knowledge to all that relativistic muck. I see a light as a tool for a job. A different job requires a different tool. But that doesn't just mean that it's ok to say, "well, I think that such and such a tool suits such and such a job better," and not provide reasons to back up such a claim. Of course subjective experience plays a role here, but so do objective facts. This post is about reasons, and I want to encourage others to give their reasons. Together we can reason together, inform our opinions, and progress to real knowledge to better guide our future decisions.

The reasons that you provided in favor of LEDs for caving seem very compelling, and, I submit, help to further add to the body of knowledge here at CPF. I hope some of the reasons I and others have provided have added to this body of knowledge as well - perhaps providing information as to why incans can be helpful in other outdoor situations. Personally, I will be taking both an incan with me as well as an LED for hiking and camping. Thus the best of both worlds, color rendering when I really need it, and runtime when I need that as well.


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## Patriot (Jun 18, 2007)

> mdocod said, "So, in retrospect, the quantity in conjunction with efficiency in this circumstance, weighs so heavily in favor of modern LEDs, that it's very difficult to justify the use of incandecent regardless of the quality of the light."
> 
> Coming from mdocod, this says a lot. Like him, I really like incans but the senario window for their use seems to be shrinking everyday.


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## BGater (Jun 18, 2007)

I agree Wrath, an incan probably does show true color better . I simply prefer the amount of light I get with LED's over MY incans. I agree about an incan "punching" through smoke or leaves and brush cover better than an LED. Just the other night a Coon was digging in the wifes flowers, my L2D lit him up and he ran into the corn field. The Cree gave lots of light, but the coon was very hard to see and was about 3-4 rows in. I grabbed a 3D incan mag off the garage work bench and could clearly see him. It was as if the bright wall of light from the Cree was being reflected back to the point my vision was diminished a bit. Its all about what we each like and prefer, if it works well for you then its the best tool for the job at hand no matter if its incan or LED.


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## DM51 (Jun 18, 2007)

BGater said:


> I agree Wrath, an incan probably does show true color better . I simply prefer the amount of light I get with LED's over MY incans. I agree about an incan "punching" through smoke or leaves and brush cover better than an LED. Just the other night a Coon was digging in the wifes flowers, my L2D lit him up and he ran into the corn field. The Cree gave lots of light, but the coon was very hard to see and was about 3-4 rows in. I grabbed a 3D incan mag off the garage work bench and could clearly see him. It was as if the bright wall of light from the Cree was being reflected back to the point my vision was diminished a bit. Its all about what we each like and prefer, if it works well for you then its the best tool for the job at hand no matter if its incan or LED.


LOL!! So LEDs are better for coons, but how about those skunks that keep giving you problems? LED or incan for them?


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## LED61 (Jun 18, 2007)

My favorite color of light is an overdriven incan...something in the neighborhood of 3350K is the best for outdoors IMHO. I still like LED's better for indoor use.


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## Kentuckian (Jun 18, 2007)

As a person VERY new into tools of illumunation reading all this is dizzying! But I understand enough now to know exactly what I want. A WE Ratlesnake incan for my weapon and a WE Sniper w/Cree led for a belt holster/handheld. 

WrathOBunny: Thank you for such a though provoking thread!:thumbsup:


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## BGater (Jun 18, 2007)

DM51, im thinking of mounting an LED array to a sledge hammer for the varmints ! No skunks as of late, but the Coons are driving me nuts. One was in the garage the other night rummaging through everything on my work bench, round and round we went. At first he couldnt care less that I was shining him. I have found that strobe will stop them in their tracks for a little bit, just long enough to get a bead on em !


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## chesterqw (Jun 18, 2007)

unless the sun burns out,LEDs,incan or any other light source woill not be good enough.
end.


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## KingGlamis (Jun 19, 2007)

Interesting. I'm pretty new to this forum and am trying to learn a lot daily. So I went out and did a test in the backyard, incan vs. LED. Shining both lights at the dirt/grass combo, the colors were a little better with the incan and I could see contrast a little better with the incan. I took pics but my camera sucks for night pics, so they were not worth posting.

Now I'm glad I bought a Twin-Task light. So when camping I can use the LEDs for general light and the Xenon bulb when I need more light. By the way, it was not the LEDs in the Twin-Task that I compared to the incan, it was a different light that is LED only.

And I don't know about the rest of you, but I always carry 3-4 lights when hiking, so I can switch between them depending on my needs.


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## woodrow (Jun 19, 2007)

wrathothebunny said:


> Ok, I just want to clear this up once and for all - quality of light matters! Have you guys ever heard of the 4 C's of diamonds: cut, color, clarity, and carat weight? The first 3 address quality, and the last addresses quantity. Sometimes, one gets the impression that the only thing that matters to the LED fanatics on these forums is quantity - meaning lumens and runtime. Lumens and runtime have NOTHING to do with the QUALITY of the beam, though everything to do with the QUANTITY of the beam. Both, of course, are important. So......let me remind you of some factors that influence beam quality, and why they matter.
> 
> *Beam Quantity*:
> 
> ...


 
I am sick of all of these stupid threads. I do not have, (other than my e2e bathroom light) nor do I intend to buy another incan. I have had 30-40 of them in my 37 years, including over a thousand dollars worth of SF lights. I just like the white color of led's and hid's better. I do not need to be lectured about color spectrum. I understand it. I just like the cooler color better.

As to beam quality... My old SF M3, running on the 125 lm lamp had my least favorite beam ever in a decent light. Sorry, I just do not like irregular oval hotspots. I also do not like lights that dim after the first few minutes of use....oh wait, they are usually called incans. I did not even keep my Pila gl4 with its 550 luman (bulb not torch) light for more than a couple of weeks. My e2d lasted 4 days before it went into the b/s/t section.

So is it enough to let just let people buy and like what they want? If you think incans are better, great!!! keep buying them...pretty soon you will be able to find them in museums all across the country...right next to 35mm film and CD's. But quit trying to "enlighten" us. Many of us know more about incans than you do. We have just chosen to move on to something which is at least for us....better.


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## Cerbera (Jun 19, 2007)

wrathothebunny said:


> Mdocod,
> 
> I think you may have misunderstood the message of my post (I apologize if that is not the case). I am not saying incans are better or even more preferable to LEDs. I did not post a LED vs. incan thread, though I understand it has been misunderstood to be that by some. I am trying to bring some perspective to the advantages of incandescents, the kinds of advantages that go into the cost-benefit equation that, on the other side, balances the efficiency advantages of LEDs. In some circumstances, the equation tips in favor of LEDs, in other circumstances, the equation tips in favor of incandescents. I know you stated that it is all a matter of opinion, that there is no right or wrong. I don't see it that way, I see it as an equation that incorporates objective factors in addition to the unique subjective experiences of the individual.
> 
> ...



Agreed. However...



woodrow said:


> So is it enough to let just let people buy and like what they want? If you think incans are better, great!!! keep buying them...pretty soon you will be able to find them in museums all across the country...right next to 35mm film and CD's. But quit trying to "enlighten" us. Many of us know more about incans than you do. We have just chosen to move on to something which is at least for us....better.



Very enlightening...

Indeed the debate will always go on but its been said many times on this thread that it really is all about preference.

I just purchased my very first Cree for my Z2. After that, I might buy an HID to see if its better than my Mag85. My curiosity won't stop as I buy new and exciting technology.


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## yellow (Jun 19, 2007)

woodrow, no need to be this direct. 
Maybe some time the incan guys will also realise, that they compare lights, running on at least double power from the battery, with way less powerful ones.
Maybe sometimes they will notice that the only fair incan light to compare any powerful led light with is a 3P.
Then, and only then, all those color rendering or depth of view talk will be over because the 3P is lost oustside a room.


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## TigerhawkT3 (Jun 19, 2007)

I saw this thread earlier today, but I waited until I could stop by Target and get some  (candy, actually) and a new flashlight (of course...).

LED people (including me) are always so jazzed about more output because, in comparison to good incans, that's what LEDs are terrible at. With LEDs, every bit counts.

However, the incan people (including me) know that LEDs are far, far away from incan outputs. What's the most you can get from a single emitter these days - about 200L? Granted, you could just pack an array of emitters into a showerhead flashlight, but that's not so good for throw. Incans may not be impressive as average EDC lights (like an L2D-CE, U2, or Gladius), but their potential output makes them worth it. That's why I continue to get excited about planning new incan builds - the crazy output.

My LED lights far outnumber my incans, but my incans are virtually all hotwires (modded, better parts, etc.), because they're fun. Honestly, I've never investigated the "quality" and color/depth perception of my LEDs vs. my incans, because staring at the hotspot of a 600W, 12kL aircraft landing light is a reeeaaally bad idea. 

So, in conclusion: LEDs are much more useful, FOR ME, IN MY OPINION, but hotwires are lots of fun because you can get such huge output.

Yum... big numbers taste good.


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## yellow (Jun 19, 2007)

> but hotwires are lots of fun because you can get such huge output.


huge output in smaller size!!! 

again, see the problem?To get a Led light to compare, it has to be multiemitter (bigger, more expensive, not available).
When using a real hotwire and then comparing it with a consumer led light (which not even pushes the single led to its max), there is no comparing.

Compare a normal Fenix to any 3 cell (normal batts) / 800 mA incan.
No more asking of color rendering or depth of view - the incan simply is outshined. 

The other way round would be to compare a L2D with a budget 2AA light. The outcome is clear even without turning the lights on and its the same unfair thing than a 6P against a single led.


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## HarveyRich (Jun 19, 2007)

> Originally Posted by Tigerhawkt3: However, the incan people (including me) know that LEDs are far, far away from incan outputs. What's the most you can get from a single emitter these days - about 200L?


 
True enough, but most beams are very concentrated with the lumens all in a tight little spot. To me that makes them much less useful outdoors which you would like a good hot spot and nice spill so you can see the surrounding area.

Harvey


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## leukos (Jun 19, 2007)

EV_007 said:


> Interesting thread. I've always maintained that incans, despite their battery sucking, "yellow" light, are the best choice for outdoor color rendition.
> 
> I love the LEDs for their smaller size, and longer battery life, but wouldn't use them solely for quick identification of subtle targets out in the wild. Trees, leaves and general "nature" stands out better than LEDs, but at the cost of runtime and bulb life of course.
> 
> I'm still an incan guy though.


 
I'm an outdoors guy, so this pretty much sums up my uses and opinion on the matter as well.


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## TigerhawkT3 (Jun 19, 2007)

yellow and HarveyRich, you two completely missed my point. I find LEDs to be practical, useful, efficient, etc. I only EDC LED lights. HOWEVER, incans can go a lot brighter. That landing light I mentioned is the size of a 10MCP spotlight (huge) and the runtime is 5-10 minutes (short), making it extremely useless for everyday tasks for most users, including me.

...But I still like it. :devil:


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## wrathothebunny (Jun 19, 2007)

Woodrow,

You denigrate the value of the information posted here, despite several members expressing their interest in this subject. Perhaps you know a good deal about visual processing and light, but you choose instead to simply state your opinion - claiming entitlement to your own preference. But this isn't really honest now is it? You aren't claiming some subjective preference, you are claiming that incans are going to go the way of the Dodo - through (what I hope is hyperbole) saying that they'll being found in museums shortly.

Now, that my friend, is not a subjective statement - you are treading into the realm of asserting objective information. That's fine, I like objective information. But you provide no substance to back up your wild claim. So, let me get this straight, you feel that incans are going to go the way of the Dodo because you don't like them?

Please, if you are going to try to discuss real issues in these forums, try to provide some substance to your comments rather than just throwing the weight of your opinion around. After all, you seemed to imply that you have a great deal of knowledge about these matters.


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## LuxLuthor (Jun 19, 2007)

I love incands because they are brighter and a more natural color, but I like LED's too. I can't say I love LED's because they give an unrealistic/unnatural color to everything....and they don't have the lumens.

It's like Jim said at the National Geographic special: 







Ain't no LED that can give that kind of horsepower yet.


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## woodrow (Jun 19, 2007)

sorry, I just was irritated by another thread where a guy got jumped all over for retireing his e2e for a Fenix. I see the value of all the above posts, but often-to many here-incans mean Surefire. Anything else is either a plaything or junk. I missed your above post that I find to be very true. Again, I apologize.

As to beam quality, it is subjective. Some of my new lights have both OP and smooth reflectors. The OP gives a cleaner, smoother beam. Yet, I and many others have the smooth reflectors in many of our lights-even though it means the beam has a ring in it. Again, personal prefernce.

I guess my main concern is that the comparing flashlights or watches or whatever to diamonds is really a stretch. The rating of diamonds is set on a pretty universal scale, to which there is 98% agreement. The rating of flashlights is purely subjective, and as seen here, agreement does not come easily. Neat idea though.


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## wrathothebunny (Jun 19, 2007)

Woodrow,

Thanks for the apology - no hard feelings. I weighed in on that thread that you were talking about in defense of that original poster, and it was absolutely shameful what some of the members said to him - just for liking his new Fenix. About your points, the diamond bit was just meant to be an analogy, and like any analogy, it falls apart if you take it to far. I agree with you, in part, that a lot about light can be subjective. But there are objective qualities as well.

A gentleman posted pictures earlier demonstrating the effect that adding a red LED to some white LEDs can have. Contrast and depth improved dramatically, I don't know how any who could look at those photos wouldn't see that. Another instance would be the penetrating power of incans through fog. There isn't anything subjective about that, the blue spectral light of the white LEDs reflects back far more than the red spectral light of the incans. This is just physics.

Contrast operates the same way. Incans provide better contrast for organic materials typically found in nature rich in the more red end of the spectrum (like dirt and tree bark, etc.). Again, not subjective, just a combination of physics and well studied cognitive processes in the brain's visual processing centers.

To take another area often characterized as subjective, art, for comparison - I will give the example of Pablo Picasso. I, personally, don't find his work very appealing. That is my subjective impression of his work. But given what I've learned of cubism, I can understand the very objective nature of how skillfully he applied that technique to his work. Take Mozart as well, someone might say they don't like his music, but there are plenty of objective reasons why he is considered one of the greats.

Again, if these analogies are taken too far, they will, of course, fall apart. I simply want to illustrate that informed, factually-based, conversations can occur in subjects traditionally considered "subjective." We all have rods and cones in our eyes. Our brains all process visual information in at least roughly the same way. Our outdoor environments usually possess organic materials such as dirt rich in the red end of the spectrum. These are all objective commonalities that we share, along with our own subjective preferences such as color temp, brightness, beam shape, etc.


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## woodrow (Jun 19, 2007)

wrathothebunny said:


> Woodrow,
> 
> You denigrate the value of the information posted here, despite several members expressing their interest in this subject. Perhaps you know a good deal about visual processing and light, but you choose instead to simply state your opinion - claiming entitlement to your own preference. But this isn't really honest now is it? You aren't claiming some subjective preference, you are claiming that incans are going to go the way of the Dodo - through (what I hope is hyperbole) saying that they'll being found in museums shortly.
> 
> ...


I do not like it when people post twice in a row as I am doing now, so I apologize in advance for doing so. Wrathothebunny, I must say first, yours is some of the most logical and well written text I have read here. As for my rant about incandescent bulbs being put into museums... like it or not, I believe it is going to happen. For the good in household bulbs, and for the bad in flashlight bulbs. I do not believe it will happen in the next year or two... but in the next five or six, most likely. 35mm and better still 120 film take better pictures than most digital sensors can (save possibly 12-16mp full frame slr's) but it is going away as well.

I believe that most enlightened led light fans know that incandescent beams illuminate contrast better at a distance. The problem is that the technology that would make incans have a greater longevity has never been put into practice except in a couple of lights. If incan's were regulated, so the light that is so great the first few minutes (the 250 luman bulb lived in my M3 and the P61 lived in my 2 cell SF lights) I would have a greater love for incans. Thats my main problem with the "incan's are greater" argument. They are greater for how long? 

Thanks again for your well worded and well thought out thread. Even if I do not agree with its premise, it was well done. I am sorry I missed you next to last post. I myself, just feel like the many who have retired their trusty film slr. It is not that digital gives me such better prints....it does not. It is just the way the world at large has decided to go...often for some pretty good reasons.


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## wrathothebunny (Jun 19, 2007)

Hmmmm....we must have been writing at the same time, but thanks for the compliment Woodrow


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## TORCH_BOY (Jun 19, 2007)

Not Knocking Incan's, I just hate Blown bulbs, otherwise there great


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## mchlwise (Jun 19, 2007)

Although I "left the thread" yesterday because I didn't feel like it was going anywhere, I read the later posts with interest. It is with some trepidation that I "come back", but it seems that Wrath has come off his "high horse" a little bit; and I'm always up for a logical reasoned discussion. 



wrathothebunny said:


> I simply want to illustrate that informed, factually-based, conversations can occur in subjects traditionally considered "subjective." We all have rods and cones in our eyes. Our brains all process visual information in at least roughly the same way.



Roughly, but not exactly. As you also state:



wrathothebunny said:


> These are all objective commonalities that we share, along with our own subjective preferences such as color temp, brightness, beam shape, etc.
> 
> ...a lot about light can be subjective. But there are objective qualities as well.



The problem I have had with most of your posts in this thread, is that you appear to have taken the position that the objective far outweighs the subjective with regards to the LED vs Incan comparison (in fact in the beginning you didn't seem to leave any room for subjectivity), that incans are better than LEDs, and that the benefits of incans over LEDs can be proven by science. 

I do not believe this position is correct. I believe that there is much more subjective than there is objective with regards to the incan vs. led comparison. 

As a perfect example:



wrathothebunny said:


> A gentleman posted pictures earlier demonstrating the effect that adding a red LED to some white LEDs can have. Contrast and depth improved dramatically, I don't know how any who could look at those photos wouldn't see that.



I didn't see that. Whether you can know how I didn't or not, I simply didn't see that. Maybe we process red differently.

Are your eyes physically significantly different than mine? Possibly. 
Does your brain process information significantly different than mine? Possibly. 

I believe, however, that it's much more likely that your PREFERENCE is different than mine, and that it is the subjective aspects of evaluating the light that lead us to our differing conclusions. 

You made an analogy to art, which is well taken. There are certain techniques in certain styles of art which are very complex, and may only be appreciated by someone who understands them fully. Most people may look at the piece and hate it, while someone "educated" can appreciate the work that went into creating it and love the piece, though they still may not think it's "pretty." 

I believe a better analogy, though, is food. I like Chinese food better than Italian food. Someone can come in and tell me all the dangers of M.S.G., or of fried foods, or spices, or whatever. You can tell me all day long how Italian food is "better" than Chinese food in this aspect or the other. You can prove to me scientifically that some of the ingredients in Chinese food will lead to my premature demise, and that Italian food is more healthy for me and on and on (FOR EXAMPLE). I would still rather have (and in fact will have) Chinese food before Italian food. 

If you were taking the Italian side of that hypothetical discussion, you could just as easily say "We all have taste buds on our tongues. Our brains all process taste information in at least roughly the same way." and you could tell me that you don't know how anyone can taste lasagna and sweet and sour pork, and not conclude that the lasagna is better. 

I believe that subjectivity plays a much bigger role in the incan vs. LED debate than you appear to believe it does. There are certain scientific, observable, measurable aspects of light, just as there are in food. Incan light may be better at certain specific things than LED is, just as Italian food has less MSG than Chinese food does. That doesn't mean I like it better. 

Which brings me to my final point... which is the right to opinion. You appear to be a very scientific-oriented person, believing that things are or aren't, that there must be reason and basis for every decision, and that opinions must be formed based on facts. You basically state that if an opinion is not backed up by facts and reason, it's not valid. 

I believe you are wrong. 

What is your favorite color? Why? Or your favorite food? Blonde or Brunette? Coke or Pepsi? Or is it 7-Up, and no cola at all? Italian or Chinese? I could go on and on with questions that point out the FACT that you have preferences which may not be based on anything other than the fact that... you like one better than the other. You have an opinion. Frequently, that opinion is not based on scientific evidence or conclusions. It's based solely on preference.

Personally, I like LED better than Incan. You may have had some interesting points, and useful information... but you're not going to change my mind with it. And I don't think you'll change anybody elses. 

The LED vs. Incan argument can't be "proven" by science... because it's mostly subjective. It's mostly... opinion.

:shrug:


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## Codeman (Jun 19, 2007)

I keep thinking of the VHS vs Beta format wars. Beta was technically superior, but VHS won out. And now both, for the most part, have been replaced by DVD and it's descendants. Hmmm......


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## Learjet (Jun 19, 2007)

So, why the need for such "pure" light anyhow? Are we all painters that need to render a scene in pure perfect natural light or sumthin? 

LED is good enough for most of my lighting needs. For more power or throw I'll use an incan. Love em both.

BTW the brain will usually correct for most shifts in colour rendering, given time. 

I also wonder if preference to LED or incan can be found in a users eyes. While I'm at wondering, which would be better for those with colour blindness? LED or incan?


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## BB (Jun 19, 2007)

wrathothebunny said:


> Ok, I just want to clear this up once and for all - quality of light matters! Have you guys ever heard of the 4 C's of diamonds: cut, color, clarity, and carat weight? The first 3 address quality, and the last addresses quantity.



And just to poke a little fun at the diamond analogy premise for this thread and use it as an example of how it does not apply at all (I hope) for flashlights.

For jewelry, it is all subjective... The ring still "works" the same regardless of the 4 C's (still gets caught in machinery, shorts batteries, gets lost down the sink, cuts off circulation, gets stolen, etc.). For the "average ring user", there is no functional/visible difference between a flawless white diamond and a good CZ or other "knockoff" except price.

And, the largest diamond merchant in the world, De Beers, could not do business in the US for the last 50 years because of charges and an eventual criminal pricefixing conviction under US Anti-Trust laws...

De Beers drives up the prices of diamonds by either owning the supply or having exclusivity agreements with most diamond sources in the world.

They also drive up prices through extensive advertising and industry trade groups (and wives). It is the old marketing phrase "...if everyone says that diamonds are expensive because they are worth it--then it must be true".

Fortunately, we do not have these issues to deal with when buying/using flashlights.

Another question on LED and CRI... Red/Green color blindness is predominately a male genetic defect. Anyone out there with R/G color blindness--how do "white" LEDs work for you vs other lighting sources (filament, HID, fluorescents, etc.)?

-Bill


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## BB (Jun 19, 2007)

Learjet said:


> I also wonder if preference to LED or incan can be found in a users eyes. While I'm at wondering, which would be better for those with colour blindness? LED or incan?



Hmmm... Looks like we think alike. :tinfoil:

-Bill


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## Learjet (Jun 19, 2007)

BB said:


> Hmmm... Looks like we think alike. :tinfoil:
> 
> -Bill



And post at nearly the same time. Spooky synchronicity.


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## jtr1962 (Jun 19, 2007)

mchlwise said:


> I believe a better analogy, though, is food. I like Chinese food better than Italian food.


I'm with you there. I still love Italian food, it's just that I love Chinese food more. No rational explanation. My preference for females is incidentally the same also-Chinese over Italian, only in this case Chinese wins by a mile. Again, just a preference with no logical explanation.



> Personally, I like LED better than Incan. You may have had some interesting points, and useful information... but you're not going to change my mind with it. And I don't think you'll change anybody elses.


Same here. The yellow tinge of even the whitest incandescents is just something I find disconcerting. It makes white walls look dirty. In general I associate the yellow bias incandescent gives everything with an old, yellowed, rundown appearance.



> The LED vs. Incan argument can't be "proven" by science... because it's mostly subjective. It's mostly... opinion.


Actually, you can scientifically prove why it subjective. Once you get past a point, CRI just isn't terribly important any more. The CRI of 75 to 80 of most white LEDs is "good enough" for most people. Few will notice or care that they aren't able to discern between certain very close shades of pastel in the context in which most flashlights are used. Once CRI gets into the mid-80s or beyond, none except a trained eye will even be able to tell the difference. Also, LEDs can make up for their CRI shortcomings by having a color temperature more resembling natural midday sunlight. This makes many colors appear more accurate even if the lower CRI makes distinguishing between certain close colors harder. This is actually why when my only general lighting choices 25 years ago were incandescent or horrid by today's standards cool-white fluorescent with a CRI of 62 I still preferred the fluorescent. I knew some it wiped out the ability to distinguish between some colors, but I accepted this in return for the more natural appearance of whites/neutrals. In other words, the color rendering issue probably comes down to a wash. That leaves only other, much more subjective factors to use as a basis for defending your preference. This is the scientific explanation of why these arguments are pretty much subjective.


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## seery (Jun 19, 2007)

For my needs it comes down to this...

LED = Indoors

Incan = Outdoors

These days it's all Surefire A2's and M6's.


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## wrathothebunny (Jun 19, 2007)

ahhh...so it's to be a subjectivist/objectivist debate? Well, I'm busy right now, but I'll post some good stuff to address this later this afternoon. Till then


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## yellow (Jun 19, 2007)

*oh, there is a third tread dealing with this topic*

I will mark this and the other treads and will post links into the one future tread, dealing with that "supergreat and powerful" SF MULTIemitter, that they will build when their Cree models received positive talk but the critic that they _are too dim_

Suddenly everyone will have "known from the beginning", that 

leds can be bright
perfect in- and outdoors
but need to be multiemitter to give the requested output

I type now, that this light will be a three emitter setup and would say "within one year from now on" (= till Summer 08)


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## Owen (Jun 19, 2007)

wrathothebunny said:


> So then you feel that the Sun at sunset/sunrise is not full spectrum then, as it's tinted warmer? You are confusing "full spectrum" with color temperature. You can have a full spectrum light tinted towards blue, with a CRI of 100, and you can have a full spectrum light tinted towards yellow, with a CRI of 100. You can also have a completely "neutral" tinted light, with a color temp in the range of 5000-5500 Kelvin, that is not full spectrum, with a CRI of 70 (hell, for the sake of argument you could have it at 1). Read through the earlier posts, there has been much information posted that covers all this.



I'm not confusing anything, and you can spare me any so-called explanations, because I know this is just a troll post that I'm falling for just by responding to. It has apparently misled some people, though. 
There is no practical value to "full spectrum light". Any time I see someone use that terminology here, it immediately tells me that they don't know what they're talking about. It's a marketing term, a fallacy. It's a misnomer that indicates the light source is putting out everything from infrared to ultraviolet. It has nothing to do with equal degrees of light between wavelengths, it has nothing to do with color rendering, and it has nothing to do with any practical aspect of a light's use.
You can have a CRI of 100 with different tints, yes, and with dramatic differences in color rendition. 
If nothing else, that should tell you just how little the "color rendering index" means.


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## VF1Jskull1 (Jun 19, 2007)

And that's why i have both incans and led's........


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## wrathothebunny (Jun 19, 2007)

Owen,

The term "full spectrum" has been used as a marketing buzz word, and often times it is applied inappropriately, so then it does, I agree become meaningless. That is not how I am using this term here, however. If you go back to my initial post, you will see that I characterized the spectral quality of the light as consisting of both the color temperature, as well as the color rendering index (I find it interesting that you missed this). Both of these are important. The "full spectrum" is important so as to render ALL colors with clarity and contrast, the color temp bit helps determine where the emphasis falls in that range. If you wish to offer a compelling argument for how a light-source deficient in the red end of the spectrum, such as white LEDs, can better render organic environments, please, be my guest.


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## Bertrik (Jun 19, 2007)

mchlwise said:


> The LED vs. Incan argument can't be "proven" by science... because it's mostly subjective. It's mostly... opinion.:shrug:


Exactly! LEDs are different from incans, but neither is necessarily superior to the other: LEDs generally lack in red and incans generally lack in blue (even though they may have a high CRI). I've personally seen a stronger washout effect from LEDs in a natural environment, but also noticed better color discrimination from LEDs up close.


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## wrathothebunny (Jun 19, 2007)

My post did in no way suggest that LEDs or Incans were superior to one another. My post specifically dealt with rendering of contrast, depth, and detail in natural environments. Also, while incans are more heavily weighted toward the red end of the spectrum, they still have plenty of light left in the blue, particularly the 3200-3300 Kelvin incans. LEDs, however, are severely lacking in red wavelength output, and this drastically affects color and contrast rendering of environments where colors more rich in reds abound. This is exasperated by the fact that human visual reception is far more sensitive to blue light than to red light. The science of visual sensory processing is actually surprisingly mature, and the amount of empirical knowledge out there that addresses these visual topics and more is astounding. To say that science can't address these topics is untrue, rather, perhaps, you could say that you have not yet read any science that has addressed these topics.

[Edit] I mentioned before that I would add some more material for the whole subjective vs. objective thing. I apologize, but I worked like a dog today and need to retire. I do have some material I want to post, but it will have to be tomorrow.


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## Robban (Jun 20, 2007)

I've lost track of how many of these threads I've read but needless to say they're always entertaining


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## wrathothebunny (Jun 20, 2007)

Ok, the point has been made that visual perception of light as it relates to one's environment is far more subjective than it is objective. This is a very complex issue, so some definition needs to be brought to it so that it can be intelligently addressed.

*What Visual Perception is:*

Visual perception is the process of forming cognitive representations of photonic input from the environment as received through the eyes. It doesn't just address how the eyes as an organ respond to light, but it also addresses the perceptual processing that occurs after the input of light to the eyes. It is a continuous process, and prior visual stimuli and responses will impact subsequent visual processing biases (this term used in a good way).

*What Visual Perception is Not:*

Visual perception does not include the higher-order cognitive processes that take place after the process of constructing cognitive representations of the environment occurs. So, visual perception does not DIRECTLY relate to your how you feel about light, though the perceptual process will likely influence it. If your favorite color is blue, this is not visual perception. If you like black and white photographs more than color photographs, this is not visual perception. If you like the whiter or bluer tint of LEDs over the yellow tint of incans, this is not visual perception, it is how your higher-order cognitive processes combine to determine how you feel about the visual input you have received.

Now, the argument has been made that visual processing is more subjective than objective, this is patently false. There is so much information out there on the KNOWN mechanisms in visual processing found in normally functioning humans for this statement not to be false. I will give you an example.

I want to introduce you to the perceptual concept of "feature detectors." Feature detection is something your brain, not your eyes, but your brain does right after receiving visual stimuli down the optic nerve from your eyes. You are not conscious of feature detection, this occurs before you are even aware you are looking at something. A very basic example of feature detection relates to lines. Your brain actually has detectors that will immediately detect whether a line is vertical or horizontal, curved or straight. A horizontal line is easily discriminated from a vertical, and a curved line is easily discriminated from a straight one. However, a diagonal line will activate both horizontal and vertical feature detectors, and is, therefore, more difficult to detect among existing horizontal and vertical lines. Here is a neat demonstration of this effect.

Please find the "V"s in the following block of letters.

LLLLLTLTLTLTTTTTLLTTLLTTTLTLLLTLLTLTLTLLTTTLL
LTLLTTTLTLLLTLVLTLLTLTTLTTLLLTLLTLLTLTTVLTLLT
LLTLTTTLTLLTLLLTTTLTLVLTLTLLTLLTTTLTLTLTTLTL

There were only 3 "V"s, how long did it take you to find them?

Ok, now find the "O"s in the following block of letters.

LLLTTLTLLTTTLTLLLTLTLTLTLTLOLTTLTLLTLLLTLTLTL
LTLLTLTTTLTLTOLTLTTLLTLLTLTLLLTLLTLTTLLTLLTLL
TLTLLTTLLTLLTLTLLLTTTLTLLTLLTLLTLLTOTLLTLTLLLT

There were 3 "O"s, did you find them faster? You should have. Having only 3 lines of text and only 3 target letters allows for some chance of error, but I guarantee you that scanning several lines of text this way will invariably result in faster detection of the "O"s.

The curved "features" of the "O"s allows fast discrimination between the "O"s and the horizontal and vertical "features" of the "L"s and "T"s, while the diagonal characteristics of the "V"s possess both horizontal and vertical "features" thereby failing to discriminate as well, and requires more in depth scanning.

So, is this subjective or objective? Science has helped demonstrate that this visual processing mechanism is common among humanity, and so it is objective. Whether you like "V"s or "O"s better is of course, subjective.

This demonstration should help to illustrate that the more discriminate the details are from each other in the environment, the more readily they can be identified. So, for contrast, I will give you a similar demonstration.

There is one lighter M, and one darker M, can you find them?

MMMMMMMMMMMMMMMMMM
MMMMMMMMMMMMMMMMMM
MMMMMMMMMMMMMMMMMM
MMMMMMMMMMMMMMMMMM

The "M" third row down, 6th from the right is a darker orange, and the second row, 3rd from the left is the lighter orange.

Now, I've taken the lighter orange as my background letter, and put in darker orange for the target M, can you find the darker orange M?

MMMMMMMMMMMMMMMMMM
MMMMMMMMMMMMMMMMMM
MMMMMMMMMMMMMMMMMM
MMMMMMMMMMMMMMMMMM

The darker orange M is in the third row down, 5th from the left. You should have found this much easier (otherwise you might want to calibrate or look for a new monitor, perhaps).

The effect of this demonstration was an increase in contrast between the "details." I hope you can see why having greater contrast outdoors helps to better identify the details in your environment now. In order for the colors to be properly and more distinctly rendered, the corresponding wavelengths from your lightsource must match the colors found in your environment. For example, a lightsource high in blues, greens, and yellows, will render orange and red colors to appear much more similar to each other than a lightsource rich in yellow and red wavelengths. The benefit of higher CRI, and more full spectrum light, is that these wavelengths are all there in adequate quantity to effectively discriminate red from orange, yellow from green, green from blue, etc.

*So what is the question?*

The question is not what light pleases you more, or if you prefer how light renders some subjects more than others. The question I addressed in my first post is what current flashlight options produces the quality of light that provides for the most UTILITY _(edit: meant to address utility in rendering visual detail, see definition in post #111)_ in rendering outdoor environments. This is not a subjective question, but an objective question that can be answered with empirical information BECAUSE visual processing at its basic level is so common among humans as to allow it.


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## WNG (Jun 20, 2007)

1. Empath said it best and saw this coming...as usual.


2. I don't hate incans....I think they are great, I just bought two 3D Mags for $9 ea, to swap in O-lips and CREEs and SSC P4s.


3. Wrathe...
your soapbox post is just that....your opinion. Something you seem to overlook when comparing it to others' replies on their opinion of what is important in a portable light source.
Fact, white LEDs currently have inferior CRI. Not many of us disputes this.
BUT, CRI is but only one criterion in evaluating a PORTABLE light source.
Others point that out that the criteria for personal choice is weighted. But you dismiss this and made CRI the absolute and only factor is lighting performance. What you seem to not understand is that such bold statements is only your opinion. Not that the rest of the cpf community is uneducated and misinformed. That's why you've been accused of arrogance and alpha-centric. 
Reminds me of another reply to such comments...
"How mighty white of you."

To take the liberty to post such a thread and respond in such a manner means you should be comfortable in receiving likewise.

4. I still have incans, they are still the best bang for the buck when high output is required. I deal with their shortcomings. But HID and LEDs are superior performance wise when you weigh efficiency, ruggedness, MTBF.
And LED development will continue onward as they are the future. 

5. FYI....
I also love Chinese and Italian food, my two favorites over everything else by a large margin. But I do prefer Chinese food more.
But when it comes to women, I prefer Italian women over Chinese women.

My significant other is Italian, and if I didn't state the above, she'd leave me with no teeth to eat Chinese or Italian food!


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## wrathothebunny (Jun 20, 2007)

WNG,

You seem to be stating that all knowledge is only opinion. I disagree. Perhaps you would like to say that gravity is an opinion, and that perhaps one person finds that when they jump up, they keep on going, but when others jump up, they fall down. No, you would probably dispute this and say that Physics is the realm of science, but vision is not. I am sorry to correct you, but visual processing is very much the realm of science. Perhaps you should take up your beef with all the cognitive researchers investigating visual processing phenomenon, and tell them that their work is a waste of time, after all, its all subjective and opinion according to yourself.

[Edit] I also find it interesting that you completely disregarded my post, when I specifically state that I am NOT, I repeat NOT, debating about what people find pleasant, but rather the utility of an illumination tool as it corresponds to well studied visual processing mechanisms.


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## Empath (Jun 20, 2007)

wrathothebunny said:


> The question is not what light pleases you more, or if you prefer how light renders some subjects more than others. The question I addressed in my first post is what current flashlight options produces the quality of light that provides for the most UTILITY in rendering outdoor environments. This is not a subjective question, but an objective question that can be answered with empirical information BECAUSE visual processing at its basic level is so common among humans as to allow it.



What a bunch of nonsense, guy. You can set up as much data as you wish, and then make absurd suggestions, but it doesn't alter anything. Your word "UTILITY", which you even put into caps, makes it subjective. "Visual processing at it's basic level", common or not doesn't mandate calling subjective data objective. "Utility" is subjective usefulness of anything.

What you've provided so far is opinion masquerading as facts. Even worse, it's opinions of your preferences that you've tried to dictate all men must share or be considered haters of truth and fanatics of fallacy.


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## TigerhawkT3 (Jun 20, 2007)

WNG said:


> ...
> efficiency, ruggedness, MTBF.
> And LED development will continue onward as they are the future.
> ...


He's not talking about that; he's talking about color rendering, depth perception, contrast, and other qualities of the actual light. I don't think anyone's disputing the convenience, efficiency, or rapid progress of LEDs - just the quality of their output.


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## GreySave (Jun 20, 2007)

I just knew this thread was going to be fun to observe!


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## wrathothebunny (Jun 20, 2007)

Empath said:


> What a bunch of nonsense, guy. You can set up as much data as you wish, and then make absurd suggestions, but it doesn't alter anything. Your word "UTILITY", which you even put into caps, makes it subjective. "Visual processing at it's basic level", common or not doesn't mandate calling subjective data objective. "Utility" is subjective usefulness of anything.
> 
> What you've provided so far is opinion masquerading as facts. Even worse, it's opinions of your preferences that you've tried to dictate all men must share or be considered haters of truth and fanatics of fallacy.




Empath, I respect your position here at CPF as an administrator. However, if you wish to debate me on equal footing, I would welcome the challenge. Your singling out my use of the word "Utility" as subjective is not entirely unexpected, as it is very common in debates to challenge the definition of terms. To respond to your challenge, I would define "Utility," for the purposes of my argument, as that degree to which a lightsource renders details in the environment in such a manner as to allow the viewer to more readily detect detail in the environment as it relates to form of the object, position of the object, and dimension of the object. The target environment for this discussion is the typical outdoors, with common elements including grass, trees, dirt, rocks, bushes, branches, water, etc. I also take exception to your allegation that I have misrepresented data. Please point out how I have done so. If that charge is accurate, I profoundly appologize and I will personally post a retraction or addition to clarify the error. If that charge is not founded, then I would consider it libel.


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## Empath (Jun 20, 2007)

Then perhaps you should have replaced the word "utility" with your definition, and made it say:

_"The question is not what light pleases you more, or if you prefer how light renders some subjects more than others. The question I addressed in my first post is what current flashlight options produces the quality of light that provides for the  "degree which a lightsource renders details in the environment in such a manner as to allow the viewer to more readily detect detail in the environment as it relates to form of the object, position of the object, and dimension of the object" in rendering outdoor environments. This is not a subjective question, but an objective question that can be answered with empirical information BECAUSE visual processing at its basic level is so common among humans as to allow it."_ :laughing:

Have a good time, but remember, this isn't anywhere near as important as it feels to you.


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## defusion (Jun 20, 2007)

wrathothebunny said:


> Empath, I respect your position here at CPF as an administrator. However, if you wish to debate me on equal footing, I would welcome the challenge. Your singling out my use of the word "Utility" as subjective is not entirely unexpected, as it is very common in debates to challenge the definition of terms. To respond to your challenge, I would define "Utility," for the purposes of my argument, as that degree to which a lightsource renders details in the environment in such a manner as to allow the viewer to more readily detect detail in the environment as it relates to form of the object, position of the object, and dimension of the object. The target environment for this discussion is the typical outdoors, with common elements including grass, trees, dirt, rocks, bushes, branches, water, etc. I also take exception to your allegation that I have misrepresented data. Please point out how I have done so. If that charge is accurate, I profoundly appologize and I will personally post a retraction or addition to clarify the error. If that charge is not founded, then I would consider it libel.


you see, you should've said that in your earlier post. he was right in saying the word "utility" can mean alot of things depending on the situation and required features from any tool (in this case obviously a flashlight).


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## wrathothebunny (Jun 20, 2007)

Empath said:


> Then perhaps you should have replaced the word "utility" with your definition, and made it say:
> 
> _"The question is not what light pleases you more, or if you prefer how light renders some subjects more than others. The question I addressed in my first post is what current flashlight options produces the quality of light that provides for the  "degree which a lightsource renders details in the environment in such a manner as to allow the viewer to more readily detect detail in the environment as it relates to form of the object, position of the object, and dimension of the object" in rendering outdoor environments. This is not a subjective question, but an objective question that can be answered with empirical information BECAUSE visual processing at its basic level is so common among humans as to allow it."_ :laughing:
> 
> Have a good time, but remember, this isn't anywhere near as important as it feels to you.





defusion said:


> you see, you should've said that in your earlier post. he was right in saying the word "utility" can mean alot of things depending on the situation and required features from any tool (in this case obviously a flashlight).



To Empath & Defusion,

I have been fortunate enough to have had friends and associates who enjoy philosophical and scientific debate. I can guarantee you that if one was to define all of one's terms, the simplest conversations would take hours.

I also would like to clarify that I am not advocating one technology over another, I am simply trying to bring attention to some practical advantages of incandescent light. I just as easily could have posted a thread on the advantages of LED light, and discussed runtime and lumen efficiency. I enjoy both technologies and I use both. I also am not discussing how important a technology "feels" to an individual. If someone enjoys the look of LED light more than the yellow look of incandescent light, they may justifiably choose to light up the outdoors with LED light, despite its contrast rendering disadvantages. I am not debating this.

[Edit] However, research does indicate that as light output intensity drops, most people prefer warmer tinted lighting. In this particular issue, there is variability, however the mean preference is probably around 3000-4000 Kelvin color temp for typical flashlight illumination levels at night. So the tint of 3200-3300 Kelvin incan lighting should look pleasant enough to most people outdoors, even in preference to the cooler or whiter look of LEDs. *See post #57.


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## mchlwise (Jun 20, 2007)

Empath said:


> Having such a skill at making a point, it seems a shame to lose it through a lack of people skills.



Quoted for truth. 

An impartial, open and honest discussion of this issue would have been interesting. Unfortunately, this isn't it. 

:shakehead


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## wrathothebunny (Jun 20, 2007)

Mchlwise,

It is the easiest thing in the world to do to denigrate or insult someone else. It also is the easiest thing to state one's opinion. No effort required beyond the pressing of one's fingers against the keys on the keyboard. If you think that some of the information I've posted is incorrect, then why don't you take the effort and post some empirical information to the contrary.


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## mchlwise (Jun 20, 2007)

wrathothebunny said:


> Mchlwise,
> 
> It is the easiest thing in the world to do to denigrate or insult someone else. It also is the easiest thing to state one's opinion. No effort required beyond the pressing of one's fingers against the keys on the keyboard. If you think that some of the information I've posted is incorrect, then why don't you take the effort and post some empirical information to the contrary.



The only reason I'm taking this bait is that if I leave the comment unresponded to, you will take it as a default acceptance of your erroneous statements, and fall back to the classic "he had a chance to prove me wrong and didn't so I must be right" schoolyard argument tactic.

You are too firmly entrenched in your position, and frankly in winning the "argument" and "proving" your point to hear what anyone else is saying. 

Your above-quoted post is hilarious, and you should take a moment to reflect on how the first three sentences apply to yourself.


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## mchlwise (Jun 20, 2007)

server error double post


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## wrathothebunny (Jun 20, 2007)

mchlwise said:


> The only reason I'm taking this bait is that if I leave the comment unresponded to, you will take it as a default acceptance of your erroneous statements, and fall back to the classic "he had a chance to prove me wrong and didn't so I must be right" schoolyard argument tactic.
> 
> You are too firmly entrenched in your position, and frankly in winning the "argument" and "proving" your point to hear what anyone else is saying.
> 
> Your above-quoted post is hilarious, and you should take a moment to reflect on how the first three sentences apply to yourself.




Mchlwise,

I am still waiting for you to present your case empirically. If you are suggesting that I am not holding myself to this standard, then I trust the other members' judgment here to decide the issue. I know that I have tried my utmost to provide what factual information I could. If you want to debate with me, I'll gladly do so on a level playing field. If you prove me wrong, I'll gladly accept defeat. Why would I gladly accept defeat? Because, when one is proven wrong, they gain something, they don't lose. What do they gain? At best, they gain knowledge that they did not have before. At worst, they loose misinformation. I would be happy to do either, on this subject or any other. Sometimes I get the impression that people think they gain when they shut up the opposition in a debate. When people just club each other over the heads with their opinions, nobody wins, everybody loses - because knowledge is not acquired, and misinformation perpetuates.


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## Bogus1 (Jun 20, 2007)

I would think the utility of this thread could best be measured in terms of contrasting between the two technologies (or at least should have been). For one I don’t happen to see what is wrong with that. 

There is a defensive quality that just doesn't seem to need to be here. I don't think if wrath had raised the issue of the utility of a socket wrench vs. a crescent wrench for certain tasks he would have elicited the same reactions we see here. Sure you can get either wrench to work in most instances, but who would argue one worked better than another given a certain task? It would seem pretty obvious. Perhaps in a tool forum some would argue even though there is science that could demonstrate how a hand, wrist, and arm could work most favorably for a given task with a given tool. Sure you can make LEDs work where they don't work best, and sure if you carry extra bulbs and batteries you could claim the same with incans. However there is a science to understanding the function of tools. You may prefer to do things the hard way, but that doesn't mean you are using the best tool for the job. 

I’d see an LED perhaps as a crescent wrench with general utility measured in a small package. At this point LEDS have perhaps limited the scope of the utility for incans to that of a socket set where you can get the job done faster but you need to carry extra tools and it is not pocketable, etc. If you are the guy who always reaches for the vice grips whether you are home by your tool box or not, then the distinction would seem silly indeed as would this discussion. However just as with tools, there are those who need lights to such a specialized degree most of us have never heard of them. This discussion has been limited (or should have been) to only what works best outside in a natural environment and that is not splitting hairs at all. I benefited greatly when I realized this is where incans shine as I am an entrenched LED guy myself. We should be able to discuss something this pragmatic on a flashlight forum! Let’s please try and look past the manner to see the matter that has unfortunately been hidden underneath.


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## defusion (Jun 20, 2007)

wrathothebunny, the by you provided information is very accurate and comprehensive, but if you want to get trough, try and put things into perspective for the readers.
am i right in assuming you just want to get some good information to the people, so they can make the choice that is right for them?
you started this thread with the intention of proving incandescents are better for interpreting whatever you might be looking at, but if you want to avoid a debate such as this (which isn't about anything related to flashlights or light in general anymore IMO).

what i mean by putting things in perspective, is going into the other technologies in more detail aswell, and just name some facts of different technologies, and not use any subjective stuff in your posts AT ALL (even though everyone else seems to do so). don't tell them you can see leaves better with incan's, but instead formulate it in such a way that doesn't include yourself in the sentence. you've done this in following posts, but there's still subjective matter in other posts that we can go on and on about and not get one step closer to a resolution.


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## wrathothebunny (Jun 20, 2007)

Defusion,

Thanks for the input. I try to do my best to provide the most factual account possible in my posts, and minimize subjective input that may not hold true for everyone. The art of debate and discourse can demand a lot from the speaker, and though I try to do my best, I am always looking for ways to improve as well. I do worry though that if I made my posts overly empirical, I would loose my audience as they would find it too dry and unaccessible. The original post was meant to have a little flair that would attract people's interests. Obviously it could have done without, but then I don't know that we would be having the discussions that we are having now. In any case, I appreciate your input in this manner.


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## fieldops (Jun 20, 2007)

I found this topic quite interesting. I agree that the incan is better at color rendition than current LEDs. I remember it was during our 2005 blizzard here on cape cod. At the height of the storm, it was snowing at 8 inches per hour for 90 minutes or so. winds were about 70-75mph. I was looking to dig out my truck and move it before it became impossible. I broke out my L1 and Inova XO3. Everything looked so washed out and white gray. The fast moving snow just reflected back a solid white wall. Other objects were kind of greyed out like being in volcanic ash. In order to see beyond a few feet, I had to break out the M3T. It lit up the distant objects, no sweat. The only limiting factor was the short runtime (that's why I've come to love LED lights). Thankfully, as a flashaholic, I had 6 extra batteries for the SF. 
I'm not trying to present any scientific data here, just a personal experience. The type of light does seem to matter, at least from my viewpoint (pun intended). I have to say, I do love LED lights for most work and have 80% LED lights right now. I also think eventually, down the road, LEDs will surpass incans in almost all aspects. The only thing I can say right now though, is thank God I had the SF that night. 

Can you pick out the two words of recommendation in the following text?






OOOOOOUUUUUBBBBYYYYYYY
BBBBYYYYYYUUUUUUUOOOOO
OOOOO*BUY BOTH!*UUUUUOO
YYYYYBBBBBBUUUUOOOOOOO
UUUUUBBBBBBYYYYYYOOOOO

Sorry Wrath....no offense intended.....couldn't resist 

The original visual tests were interesting though.


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## Quickbeam (Jun 20, 2007)

Been on this board for 6 years now, and every so often someone (or two) comes along and tries to inflame (incandesce?  ) emotions to try to get some point across that they hold dear. Done it myself, and I like to think I've learned since then...

Incandescents still hold a valid place in portable lighting. The do a very good job of illuminating browns and greens which are so prominent outdoors. I've noticed this frequently. They are simple and mostly reliable due to their simplicity, but horribly inefficient. Pros and cons, pros and cons. 

LEDs are up and coming technology which will eventually (we expect) will surpass the usefulness of incandescents entirely in the possibly near future. They are more easily manipulated, regulated, and are more efficient at using the energy they are supplied. They tend to have some color rendition problems out-of-doors, but indoors they frequently provide excellent utility.

Addressing a post to "incandescent haters" implies by default that the author has a serious problem with people who don't like incandescents as much as other light sources. Like it or not, this is what it implies, and the emotional responses of many who added to this thread confirm it.

Some people have a strong affinity for LEDs, others for incandescents. Trying to get people all riled up about the topic is no way to make a logical point, so again we have an implication: that making a logical point wasn't the purpose, but instead was to subimit opinion as fact and suggest that anyone who feels differently is wrong.

We are all one big community of illumination enthusiasts. We don't all agree all the time, but for the most part, we are unified in our enjoyment of this hobby. Let's not purposely try to create dissention for the sake of the personal satisfaction of making a point.

Can't we all just get along?


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## wrathothebunny (Jun 20, 2007)

Quickbeam,

I understand where you're coming from. I would like to say that I posted this thread largely in response to comments I've seen in this forum denigrating incan flashlights. I wanted the members who have been posting such comments to participate in this discussion, so it was written in such a manner as to attract their attention.

I did not write my posts to inflame members here, however. I did not say "incans are better than LEDs" or "LEDs suck" or anything like that. But we are not cyborgs, and emotion is bound to enter into our posts. I have tried to maintain a balance in the past between emotional expression and factual expression. I suppose I could just cut out the emotion bit, but that wouldn't make for interesting conversation would it? Also, I really think people are taking the "hater" thing waaaaaaaaaayyy too seriously.

In any case, my subsequent posts throughout the thread have tried to tone down the rhetoric and provide good empirical information and logical arguments. I hope some members have found this valuable.


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## Quickbeam (Jun 20, 2007)

wrathothebunny said:


> Quickbeam,
> 
> I understand where you're coming from. I would like to say that I posted this thread largely in response to comments I've seen in this forum denigrating incan flashlights.



Ah - let me add one comment here: Never argue with an idiot - he'll drag you down to his level and beat you with experience! Take the high road. It's not easy, especially when the topic is dear to heart, but it's the right thing to do. Let them denigrate incan flashlights - then provide your opinion and the logic behind it.



> I did not write my posts to inflame any members here, however. I did not say "incans are better than LEDs" or "LEDs suck" or anything like that.



You did, actually, by calling people "LED fanatics" and with comments like "So, to all you Incan haters out there, stop with all the "Incan is dead,"... ...It is ignorant."

BTW, I never suggested we were unemotional "cyborgs" - you are trying to invalidate my comments by comparing them to an "absolute": that we should never be emotional.

Yes, emotions enter our posts, but name calling is unnecessary and detrimental to calm and civilized discussions based on facts. This board is all about learning and growing. Let's try to keep it as true to that goal as possible.

Thanks for listening.


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## jtr1962 (Jun 20, 2007)

wrathothebunny said:


> The target environment for this discussion is the typical outdoors, with common elements including grass, trees, dirt, rocks, bushes, branches, water, etc.


Even this is subjective. The target outdoor environment you describe is not the outdoor environment which exists for me. Where I live I have plenty of concrete, metal lamp poles, buildings in colors other than red/brown/orange, vehicles in every color of the rainbow, pedestrians dressed in every color of the rainbow. How then will I be able to descriminate among subtle shades of cooler colors in my environment by using a light source deficient in those colors? I know every wavelength may be present in incandescent, but the relative value of those wavelengths falls off heavily in the cooler part of the visible spectrum. For me LED's color deficiencies in the warm part of the spectrum are more than made up for by its strengths in the cooler part of the spectrum. I guess what I'm trying to say is that your hypothetical outdoor environment where perhaps incandescent would hold an edge, all other things being equal, is far from typical of the environment many end users might use a light in. I can just as easily pick an outdoor environment heavily weighted in neutrals plus cooler colors, and then say LED is superior because incandescent lacks a large enough percentage of cooler colors in its spectrum to render this environment properly. We're both right and we're both wrong.

And no, I don't use incandescent at all. Even if a hypothetical 5000K incandescent existed I still wouldn't use it unless it was as efficient as LEDs, and more importantly had a reasonable lifetime (let's say 1000 hours or more for a flashlight, perhaps 25,000 hours or more for general interior lighting). It's really the horribly short lifetime of the 3200K to 3300K incandescents whose praises you sing which makes them useless to me. A lamp whose lifetime is tens of hours doesn't render colors at all once it decides to quit. That's one reason I stopped bothering with bike lighting until LEDs. Hit a pothole, and a $5 bulb is toast.


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## wrathothebunny (Jun 20, 2007)

Quickbeam,

I already responded to this. My use of the phrase "LED fanatics" was meant to be read as in "sports fanatics" not "religious fanatics." So, it was more tongue-in-cheek than anything else. Also, having the members that do disrespect incans involved in this debate was useful IMHO. Some of those members opinions have remained incalcitrant, others have seemed to respond by taking a more open perspective. Several members expressed appreciation for this debate, and I think a lot of people walked away the better for it, including myself, as I have learned from a lot of you all as well. _[Edit, I do want to thank you, however, for providing your encouragement toward more civil discourse. I do agree with that sentiment]_


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## wrathothebunny (Jun 20, 2007)

JTR1962,

Having less than perfectly precise definitions or definitions that don't match your very particular situation doesn't make something subjective. I could have written an entire page worth of specification, exceptions, etc. for my definition of "outdoors." I could have catalogued every type of tree, grass, rock, dirt, and natural formation, etc. that would be found in the various environments that would fall under my category of "outdoors." I could then have created a different treatise on every possible outdoor environment from here to the moon. Even if I did all this, you probably still could have found some small area where I was still imprecise or had missed something. As doing all this would be absurd, especially for every single definition, I am forced to rely on the reader to interpret my words with some tolerance and an understanding of what might commonly be meant by the terms. If your environment varies from the "target" environment that I described, to the degree that this occurs adjust the content here to fit your situation. _***I was editing the text on this while jtr1962 must have quoted from it, thus the discrepancy in wording***_


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## 1wrx7 (Jun 20, 2007)

I prefer the natural flicker of an oil soaked rag on a stick, but thats just my opinion.:thinking:


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## jtr1962 (Jun 20, 2007)

wrathothebunny said:


> JTR1962,
> Having less than perfectly precise definitions doesn't make something subjective. I could have written an entire page worth of specification, exceptions, etc. for my definition of "outdoors." I could have catalogued every type of tree, grass, rock, dirt, and natural formation, etc. that would be found in the various environments that would fall under my category of "outdoors." Even if I did all this, you probably still could have found some small area where I was still imprecise. As doing all this would be absurd, especially for every single definition, I am forced to rely on the reader to interpret my words with some tolerance and an understanding of what might commonly be meant by the terms.


I'm not saying we need a very precise definition of outdoors here. If your loose definition held 99% of the time then it would probably be good enough for you to base the rest of your hypothesis on. Even if I could find the 1% of the time where it doesn't apply, I'd just be nitpicking. However, your definition of outdoors is closer to what I might call wilderness, or at least very rural. It's well outside of the "outdoors" experienced by probably upwards of 50% of typical flashlight users because it totally fails to take into account manmade objects, or even people's clothing.

I'll also add that in my case, perhaps in the case of others, the allegedly greater ability of incandescent to distinguish colors at a distance is moot because I'm nearsighted. I can't see worth a darn more than 15 or 20 feet in front of me so all I need is a light good enough for that.

I wonder if the time comes when we have LEDs with near-blackbody spectrums, at least in the visible region, if threads like this will still come up, perhaps saying incandescent is better because the body somehow senses reflected infrared. I won't argue that incandescents are still useful _for some people, in certain situations, some of the time_, and where these advantages outweigh the lower efficiency, and especially much lower lifetime. I highly doubt this will still be true in 5 years as LED is still an evolving technology while incandescent has more or less run its course. So you win, at least for the time being. No disrespect to incandescent intended, either. It has a had a long, useful life, far longer than many other inventions. Like everything, it's finally reaching the end of its life.


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## wrathothebunny (Jun 20, 2007)

JTR1962,

You would be hard pressed to find 99% applicability in most applied scientific fields (take medicine for instance). In any case, what you are referring to is called "generalizeability." The typical way this is resolved is that to the degree that your context varies from the empirically presented context, you adjust based upon the variation in parameters. For instance, as the outdoor situation is (you correctly state) more wilderness and less city, then you adjust based upon how the visual parameters of those contexts differ. If your specific urban context seems particularly deficient in colors within the more red spectrum, then adjust accordingly. This doesn't make any of this subjective, it just means that it is subject to variability in circumstance as is everything else.


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## LuxLuthor (Jun 20, 2007)

mchlwise said:


> What is your favorite color? Why? Or your favorite food? Blonde or Brunette? Coke or Pepsi? Or is it 7-Up, and no cola at all? Italian or Chinese?



Purple. 
Looks cool.
Grilled Teryaki Salmon
Blonde
Coke & 7-Up (Sprite blows)
Italian



Codeman said:


> I keep thinking of the VHS vs Beta format wars. Beta was technically superior, but VHS won out. And now both, for the most part, have been replaced by DVD and it's descendants. Hmmm......


LOL....excellent point.



seery said:


> For my needs it comes down to this...
> 
> LED = Indoors
> Incan = Outdoors


Ditto



1wrx7 said:


> I prefer the natural flicker of an oil soaked rag on a stick, but thats just my opinion.:thinking:


I like this one:







I think this thread is mostly about Wrath enjoying practicing his debating skills....but there is definitely some good information among the emotions on all sides.


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## TigerhawkT3 (Jun 21, 2007)

1wrx7 said:


> I prefer the natural flicker of an oil soaked rag on a stick, but thats just my opinion.:thinking:


 I guffawed at that. You should totally make that your sigline! :twothumbs

I think I'd go with a Bic and a can of WD-40. Not much throw, but the trees and dirt in front of it will be nicely greased up. :laughing: The turbohead version entails putting the WD-40 in a SuperSoaker with a lit rag tied to the end. Now THAT'S a REAL fire-starting flashlight!


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## soffiler (Jun 21, 2007)

LuxLuthor said:


> ...I think this thread is mostly about Wrath enjoying practicing his debating skills....but there is definitely some good information among the emotions on all sides.


 
+1 on that!

I'm a bit sorry I got sucked into this one. There _has_ been some interesting info, but unfortunately, I've also seen Wrath use excess eloquence (are you a marketing guy??) to amplify basic truths into exaggerations. Then he can come back and correctly argue on the basic truth again. Nice technique.

- Wrath, I agree with your assertions that visual perception is objective and physiological, not subjective. Correct.

- Wrath, I disagree that the spectrum of modern LED emitters (take the Cree XR-E 7090 and Seoul Z-Led P4 as examples) is so deficient in red that natural outdoor scenes rich in reds and browns lose all contrast. The fact is that modern emitters do have some red content, and at worst they render reds that are slightly off-shade. The do not make all reds look like brown as you have strongly suggested and implied if not stated outright. The difference between a CRI of 80 and 98 has been described as "dramatic" and _it is not_. It is slight. I'll give you dramatic, and that's a CRI of 40. I have an LED worklight with cheap LEDs having a CRI in the range of 40, and I have an automotive wire harness bundle containing some very challenging colors - red wire with brown stripe, purple wire with pink stripe, gray wires with blue stripe, etc etc. The 40 CRI makes it almost impossible to differentiate the brown stripe on the red wire among other challenges. Yet an LED worklight with a CRI of about 78-80 renders all these colors close enough that there is no abiguity whatsoever, and that demonstration does also incorporate a halogen source as a "control".


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## wrathothebunny (Jun 21, 2007)

Soffiler,

I have not stated or implied that LEDs make reds look like browns. Nowhere have I stated that. 
They may, they may not, I haven't actually looked into it. I do believe that the more lacking in 
red an LED is (and most white LEDs are pretty lacking), the more poorly they render colors with 
red components. This is compounded by the fact that the human visual system is less sensitive 
to red light than blue light.

Also, I do my utmost to build up logical arguments, such that the empirical facts are integrated 
into a structured and transparent rationale. My arguments are free and open and anyone can 
debate any of the logical steps along the way. In point of fact, it is nearly the opposite of 
rhetoric, as rhetoric is the art of debating on form over substance, and I have done my utmost 
to bring as much substance to this discussion as possible.

Concerning your point on CRI, the metric of an 80 CRI for LEDS represents the highest end of 
the range. Right now, many people are buying Fenix's, which are very good LED torches IMHO. 
The typical CRIs from Fenix's likely fall closer to 70 than they do 80, though obviously there is 
variation (and if you get a warm white Cree in your Fenix, you could very well have a CRI of 80, 
but your chances are such that you will likely get a cooler white Cree).

If you do not feel that the difference in the lack of red spectral color in modern LEDs is 
dramatically different than full-spectrum incandescent lighting, then I suggest that you search 
earlier in this thread where a member posted the effect of adding just a little red LED light to an 
existing array of white LEDs - then come back here and let me know if you think that was 
dramatic or not - I certainly felt it was.

If you feel that my arguments are form over substance, please point to where the substance 
has been neglected, and I will do my utmost to rectify it. I hope you find my response to your 
post rich in substance, and not an attempt to beat you over the head with the form of it.

* [Edit: Soffiler, I went back and got the pictures I was talking about earlier to save you 
the trouble. Take a look. The first picture is just the plain white LEDs, the second picture 
is with the addition of a red LED. Dramatic no? ***Take a look at the red stripe and 
wheels on the toy van. Also, look at the increase in contrast and depth on the toy figure 
standing with his hands on his hips, as well as on the wheels on the toy motorcycle.***]*

http://www.stuart.w.brookes.dsl.pipex.com/DSCF2497.JPG

http://www.stuart.w.brookes.dsl.pipex.com/DSCF2498.JPG

_Huge images changed to links to facilitate loading times and to permit dial-in accounts to be particpate. - Empath_


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## soffiler (Jun 21, 2007)

wrathothebunny said:


> ...I have not stated or implied that LEDs make reds look like browns. Nowhere have I stated that.


 
Making me do the homework (which I was trying to avoid - I simply don't have a lot of free time to waste away on CPF) I went back and found a couple of your comments, which technically do not state verbatim that LEDs make reds look like browns. On that point you are correct. Your words (below) gave me that impression, however. This impression is most likely due to my own experiences with some LEDs with truly awful CRI. 

_(post 85) Contrast operates the same way. Incans provide better contrast for organic materials typically found in nature rich in the more red end of the spectrum (like dirt and tree bark, etc.). Again, not subjective, just a combination of physics and well studied cognitive processes in the brain's visual processing centers._

And this quote uses terminology that I feel is emotional and exaggerates the point you are trying to make. Can you objectively quantify terms like "severely lacking in red" and "drastically affects color and contrast" ? [emphasis below is added by soffiler]

_(post 103) LEDs, however, are severely lacking in red wavelength output, and this drastically affects color and contrast rendering of environments where colors more rich in reds abound._



> They may, they may not, I haven't actually looked into it. I do believe that the more lacking in red an LED is (and most white LEDs are pretty lacking), the more poorly they render colors with red components.


 
"Pretty lacking" needs further quantification or else I'll suggest you are delving into subjectivity here. While, again, this statement above is technically correct - the problem is that it ignores an objective sense of scale or signficance. Does a small loss in the red end of the spectrum lead to a large change in color rendering? Or is it fairly linear? Or does a substantial loss in the red lead to only a fairly small change in color rendering?



> This is compounded by the fact that the human visual system is less sensitive to red light than blue light.


 
Disagree. Take a look at the photopic luminosity function:

http://en.wikipedia.org/wiki/Luminosity_function

Given the amplitude of response as a function of wavelength, it can be shown that a 440nm blue has exactly the same photopic response as a 675nm red.



> If you do not feel that the difference in the lack of red spectral color in modern LEDs is dramatically different than full-spectrum incandescent lighting, then I suggest that you search earlier in this thread where a member posted the effect of adding just a little red LED light to an existing array of white LEDs - then come back here and let me know if you think that was dramatic or not - I certainly felt it was.


 
OK, done. Nope, _not_ dramatic, to me. Significant? Yes. Dramatic, no. I seem to have a monitor problem, however, because I can't even find the truck, never mind the red stripe on the truck, on either shot. I see a fuzzy dark rectange below the woodgrain in both images so I guess that must be it. But these are academic differences. In the real world, I don't believe that MOST people are carrying both an LED and an incan torch and using them both in rapid succession on the same targets. That's essentially what showing me two pictures is doing. Instead, navigating the real world with one torch of either type, the auto-adjusting function within our own brains compensates for color shifts.



> (Edit: Soffiler, I went back and got the pictures I was talking about earlier to save you the trouble. Take a look. The first picture is just the plain white LEDs, the second picture is with the addition of a red LED. Dramatic no? ***Take a look at the red stripe and wheels on the toy van. Also, look at the increase in contrast and depth on the toy figure standing with his hands on his hips, as well as on the wheels on the toy motorcycle.***)


 
Signficant, yes, dramatic, no. Can you provide a solid objective explanation of this quality you refer to as "depth"? I'll certainly agree on one point: the chest of the toy figure contrasts better with the garment when red is added.

So... your point about enhancing contrast has been illustrated. Is it dramatic? Is it even signficant? Not to me. Would I tend to like/prefer (subjectively) the LED with added red? Quite possibly not. The overall quality of the light is decidedly pinkish and subjectively I don't like it.


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## Empath (Jun 21, 2007)

Wrath, your images have been changed to links, since the size and resolution of them are prohibitive for anyone other than the most patient that are on dial-in.

Hopefully, you've read our rules and understand our rules regarding hot-linking. I can't say for sure that the images were hot-linked, but the circumstances are suspicious. The images come from a UK broadband provider, and you're posting from a U.S. broadband provider. Not knowing every potential possibility for how you might have considered the image use acceptable, I'll stop short of actually calling it hot-linking.

If you'd like the images shown, then make them acceptably sized, and use a host under your own authority.


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## wrathothebunny (Jun 21, 2007)

Empath,

Thanks for clarifying me on the rules. The links to the pictures are not my own, they were originally posted by RustyKnee (to which credit is due), so I have no idea about his image servers, I just copied and pasted the links that he listed on his post.

Soffiler,

Your comments on blue vs. red sensitivity are patently wrong. If you look at the scotopic visual curve, you would realize this. This curve can actually be found on the link that you provided, and it more directly relates to the lower luminance values produced by flashlights when compared to daylight (to the degree that your flashlight is very bright, adjust accordingly, but you will still fall closer to the scotopic curve than the photopic curve). I understand your desire for me to be more precise, and I have made every effort to do so. I am not, however, going to write an entire visual perception dissertation for this thread just to satisfy that desire. If you have very specific issues, I am happy to clear those up, and I trust that I have addressed your red vs. blue sensitivity issue here *see image below for scotopic sensitivity*

The Scotopic (low light) curve is the one to the left, the Photopic (high light) to the right. Mesotopic (medium light), of course, would fall somewhere in the middle.


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## soffiler (Jun 21, 2007)

wrathothebunny said:


> ...I trust that I have addressed your red vs. blue sensitivity issue here *see image below for scotopic sensitivity*


 
Absolutely not. Please provide a clear reference that indicates the scotopic curve is applicable in this case.


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## wrathothebunny (Jun 21, 2007)

Soffiler,

Please see above, I just edited my post to include the scopotic vs. photopic curve. For how applicable the scotopic curve is to flashlight use, please remember that the vast majority of most flashlight beam space is spill, and LED lights typically are very diffuse anyway, with less tight hotspots found sometimes with incandescents. The lumen output of a very powerful Fenix P3D on turbo is perhaps 120-130 torch lumens (160 emitter lumens). A standard household incan bulb can be 800 Lumens, and several of these can be lit at once. The sun, of course, is a whole lot of lumens and meant to more accurately reflect the scotopic curve. In any case, flashlight use could fall in the mesopic curve, so just look at the region between the two curves for what that could look like. This should be common sense.


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## soffiler (Jun 21, 2007)

Wrath: you might find this reference interesting:

http://hyperphysics.phy-astr.gsu.edu/hbase/vision/bright.html

Note that scotopic vision is primarily a function of the RODS in the eye, and photopic vision adds CONES (color). Thus, if we are seeing colors and debating color shifts, _it is photopic vision_.


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## wrathothebunny (Jun 21, 2007)

Soffiler,

Thanks for the link, but I advise you to go to the bottom of your reference and read what is written there. It specifically says, and I quote, "rods do not see red." That's right, your rods do not pick up red at all. As the dimmer the light gets, the more your vision relies on the rods, and the less it relies on the cones. Why? Because rods are more sensitive than cones, and rods are used to pick out illuminance information, and cones pick up color information. In any case, when is the last time you saw in black and white at night? See, you never completely lose the use of your cones in dim light, it is the proportion in cone to rod use that differs. However, in dim light, your rods are not picking up the illuminance information from red light at all, though they are picking up blue, green, and yellow light just fine. Your cones are still operating, so red light is being picked up by them, but as they are not as sensitive as rods, this provides for lesser illuminance information. Your brain, then, will combine the rod's black and white info with the cones color info, and produce a cognitive representation. So even though the rods record in black and white, that data will be used to construct a color picture when supplemented with data from the cones. So at night, if you took a very dim red LED, you could see by it, but not well. If you took an equivalent blue LED, you could see very well. However, incandescent light has loads of red spectral emissions, so this aids greatly to enhance red color perception. If you don't believe me, go into the dark outdoors with a red photon light and a blue photon light, see which one illuminates better and report back here.


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## soffiler (Jun 21, 2007)

wrathothebunny said:


> Soffiler,
> 
> Please see above, I just edited my post to include the scopotic vs. photopic curve. For how applicable the scotopic curve is to flashlight use, please remember that the vast majority of most flashlight beam space is spill, and LED lights typically are very diffuse anyway, with less tight hotspots found sometimes with incandescents. The lumen output of a very powerful Fenix P3D on turbo is perhaps 120-130 torch lumens (160 emitter lumens). A standard household incan bulb can be 800 Lumens, and several of these can be lit at once. The sun, of course, is a whole lot of lumens and meant to more accurately reflect the scotopic curve. In any case, flashlight use could fall in the mesopic curve, so just look at the region between the two curves for what that could look like. This should be common sense.


 
I asked you for a reference. The above is not a reference; those are just your own assertions. A reference points to a source that can be independently verified.


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## soffiler (Jun 21, 2007)

wrathothebunny said:


> Soffiler,
> 
> Thanks for the link, but I advise you to go to the bottom of your reference and read what is written there. It specifically says, and I quote, "rods do not see red."


 
Yes. That merely explains why the scotopic response curve is shifted left (toward blue). You are ignoring the fact that the previous five pages of posts are debating the perception of COLOR which requires CONES to detect. It is factually correct but irrelevant that rods do not see red. You're just being obtuse.

I started off with an indication that I already regretted getting sucked into this thread, and I have little time to waste. Yet here I am wasting more and more. I am done here.


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## wrathothebunny (Jun 21, 2007)

Soffiler,

Have you ever lighted a candle, just a single candle? Do you know how low that level of illumination is? Ok, now, when you are seeing with candlelight, do you see in black and white or color? Your article is not making the argument that if you see in color, you must be responding to the photopic visual curve. That would be the equivalent, for most intents and purposes, of saying that any time you see you are responding to the photopic curve. If candlelight, and, hell, even moonlight allow you to see colors, then when would you submit the scotopic curve comes into effect? Here is the long and short of it, you are always using both rods and cones to see, its just that the proportion of cone to rod use will differ. However, your brain is very smart at combining the black and white input from the rods with the color input of the cones to provide for a complete, whole, color picture. Even if you are receiving 95% black and white input from rods and only 5% red color input from cones, you will still be able to perceive a red object, albeit with lower saturation and contrast.

[Edit: Soffiler, in your previous post you mentioned that you could not even see the black toy van in the picture. If your monitor is not providing you with the contrast necessary to see the black van, then how can you even comment on the image at all? Please find access to or borrow a better monitor, I recommend a good CRT as some LCDs can have contrast issues, and look at the image. You comments on it don't make any sense at all, if you can barely make out key elements of the picture. Also, you want me to define "depth" for you, well I would define it as the appearance of (accurate) 3-dimensionality. However, if you can't even see the toy van in the picture, there is no way you'll be able to detect what has more depth, again, borrow someone's monitor]


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## mchlwise (Jun 21, 2007)

soffiler said:


> You're just being obtuse.
> 
> I started off with an indication that I already regretted getting sucked into this thread, and I have little time to waste. Yet here I am wasting more and more. I am done here.



He's been obtuse throughout this thread. :green:

Steve, the only reason I'm posting in this thread again is to thank knowledgable and professional people such as yourself for your presence here at CPF. Your professionalism, knowledge, and openness to input and suggestions from CPFers is most welcome and appreciated.


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## wrathothebunny (Jun 21, 2007)

Mchlwise,

Weren't you going to offer some empirical contribution or something? What input have you provided? _*obtuse: not quick or alert in perception, feeling, or intellect, dull.*_ Again, you're at it with the insults with no substance. If you have a disagreement with the facts presented here, please make it known in a specific way so that it can be addressed, otherwise you're just flapping your trap.


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## Archangel (Jun 21, 2007)

Scotopic vision is the scientific term for human vision "in the dark", below 0.034 lm/m2. In the range above 3.4 cd/m2, the human eye uses photopic vision. In the intermediate range, mesopic vision combines both types. 

http://www.schorsch.com/kbase/glossary/scotopic_vision.html


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## 2xTrinity (Jun 21, 2007)

One point that I will make is that now I believe a lot of the major drawbacks of LED lights -- namely their weakness in penetrating fog, and the "flattening" effect, are not entirely based on spectrum, but have a lot to do with optics and beam characteristics.

For example, typical HID and incan lights are typically much more concentrated, they emit light from a filament or arc with higher surface-brightness with the LED die, and they emit light in all directions. In a reflector based light, usually 2/3 or more of the overall output is collimated as throw. In the case of relfector-based LED lights, the ratio of throw to spill is reversed. Out in the fog, this is what causes problems -- the blue component of the bright spill is the most prone to getting scattered and reflected, combine that with high scoptopic sensitivity to blue light, and the reflected light dramatically obscures the target -- whcih is already receiving a lot less overall light to begin with. 

LED lights that I have built that implement optics however have beams closer to most incandescent flashlights -- highly concentrated throw, and less spill. In the fog, these perform fine, and provide better depth perception than other reflector-based LED lights, even though the reflector lights have higher-quality more neutral-white emitters. Comparing LEDs and incans of similar overall output _and_ beam characteristics, I still notice that the Incan has an edge difference, but it's not nearly as pronounced.

Ultimately though, I'm looking forward to the day that somebody releases a 4000K dual-phosphor LED with over 90CRI (no technological reason why this shouldn't be possible), IMHO that would be the ideal spectrum for use in a flashlight -- essentially the same as the spectrum of the full moon.



> Scotopic vision is the scientific term for human vision "in the dark", below 0.034 lm/m2. In the range above 3.4 cd/m2, the human eye uses photopic vision. In the intermediate range, mesopic vision combines both types.


That same article goes on to say that mesoptic vision is in effect around dawn/dusk. Both of which are situations with a lot more light than we'd typically see outdoors, at night, with flashlights.


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## jtr1962 (Jun 21, 2007)

I think under about 0.1 lux is when you're essentially seeing things in black and white. As for candles, you may technically be able to distinguish warmer colors, and it may technically have a CRI close to 100, but I find candlelight just awful for seeing. The contrast is horrible, plus there is just no white point.

As for contrast, which is something different from color perception, it is a well documented fact that higher color temperature sources provide increased contrast at scotopic and mesotopic light levels. The best example of this is sodium vapor versus metal halide. Sodium vapor lights can be replaced with metal halide lights which have lower wattages and lux levels on a light meter, yet still offer improved contrast (ability to see details). I see this effect for myself in parking lots when sodium vapor is replaced by metal halide. It's as if a veil was lifted from in front of my eyes. Even in foggy conditions, often given as the reason for using sodium vapor for better penetrating power, I notice the metal halide is better. The metal halide may be more deficient in the red portion of the spectrum than the sodium vapor, but it has more light in the wavelengths that matter. Sodium vapor is very similar to incandescent, and metal halide to HID, at least in regards to color temperature/overall appearance, so a similar argument can apply.

There is no arguing that the red wavelengths present in incandescent reflect off objects with red in their color spectrum, and that LEDs which lack these wavelengths obviously can't do this. The problem is at the low light levels of the returning light our eyes are incapable of receiving this reflected red light to any great degree, _so it might as well not even be present_. I could argue that at low light levels, ability to distinguish between shades of red doesn't exist _regardless of the light source_. The scotopic curve more or less supports this argument. No arguing incandescents can be better with reds than LEDs in photopic light levels, at least until LEDs are improved a bit. However, this is not applicable if we're talking about flashlights where the scene might only be lit up to a level of a few lux or less.

Regarding CRI of LEDs, I believe the warmest shades of some cool-white LEDs, like the WH CREE XR-E with a CCT in the 5000K area, can approach 85. This is in the same ballpark as a high-quality triphosphor fluorescent tube. Not perfect, but few will notice the difference between a CRI of 85 and one of 100. I'm hard-pressed to tell the difference between my CRI 86 and CRI 91 tubes, for example.


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## wrathothebunny (Jun 21, 2007)

Archangel said:


> Scotopic vision is the scientific term for human vision "in the dark", below 0.034 lm/m2. In the range above 3.4 cd/m2, the human eye uses photopic vision. In the intermediate range, mesopic vision combines both types.



Archangel,

You are correct, flashlights use at night would correspond to mesopic visual sensitivity. I thought I mentioned that, I just couldn't find a curve show what that would look like (probably because there is no single mesopic curve, but a range within which it would fall), so I suggested looking between the regions of the scotopic and photopic curves.


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## wrathothebunny (Jun 21, 2007)

JTR1982,

There is a lot of misinformation in your post. First of all, Cree's product literature clearly indicates that the CRIs of their warm LEDs fall at 80, so your 85 statistic must have been pulled out of thin air. Second of all, metal halide lamps and sodium vapor lamps differ dramatically in CRI, with high pressure sodium vapor lamps with CRIs between 22-75, and metal halide lamps with CRIs between 65-80, so differences in rendering are more likely due to CRI difference rather than strictly color temp. *while there is some overlap, there is no reason to suspect that your sodium vapor lamp fell at the very high end of CRI and your metal halide lamp fell at the very low end of the range* Thirdly, night flashlight use does not correspond to scotopic visual sensitivity, but rather mesotopic visual sensitivity, which falls between the scotopic and photopic curves. Finally, the candlelight example was not meant to hold it up as a better lighting choice, it was meant to illustrate how color vision occurs at even exceedingly dim lighting levels. I think in part you recognized this, but then you went on to denigrate candlelight quality - this makes no sense to me given the context in which it was presented.


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## jtr1962 (Jun 21, 2007)

2xTrinity said:


> One point that I will make is that now I believe a lot of the major drawbacks of LED lights -- namely their weakness in penetrating fog, and the "flattening" effect, are not entirely based on spectrum, but have a lot to do with optics and beam characteristics.


Yes, I've felt that way as well, and my observations with metal halide versus sodium vapor streetlights have more or less confirmed these feelings. Both have a similar beam patterm. If indeed yellow light is better at penetrating fog, then the sodium vapor should win hands down. This is not the case. I've found that metal halide is just as good, even in cases where a lower wattage metal halide bulb was substituted for sodium vapor, meaning lower lux levels. Now if only I can convince the city to replace those awful sodium vapor lights with either metal halide or LED. For the last 35 or so years they have ruined the aesthetics of going out at night.


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## Archangel (Jun 21, 2007)

That is far too encompassing a statement. I think we very easily knock ourselves out of mesotopic vision with most of our torches.


wrathothebunny said:


> Thirdly, night flashlight use does not respond to scotopic visual sensitivity, but rather mesopic visual sensitivity, which falls between the scotopic and photopic curves.


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## knot (Jun 21, 2007)

Incans are for autumn:nana:


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## wrathothebunny (Jun 21, 2007)

Archangel,

It may well be too encompassing, so I apologize for not being more precise. However, for most LED torches, the lumen output, I seriously doubt, would exceed dawn and dusk levels - and mesopic vision corresponds to dawn and dusk levels. A SureFire M6 with a 500 lumen high output bulb, well, that would be clearly photopic any way you look at it


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## jtr1962 (Jun 21, 2007)

wrathothebunny said:


> There is a lot of misinformation in your post. First of all, Cree's product literature clearly indicates that the CRIs of their warm LEDs fall at 80, so your 85 statistic must have been pulled out of thin air.


I'm not talking about their "warm-white" LEDs. It talking about the warmer bins of their cool-white LEDs. They state the CRI of a typical cool-white LED is 75 to 80. They also state the typical CCT as 6500K. It follows then that a slightly warmer cool-white LED with a CCT of 5000K would have a CRI of 85 or so. I've even compared a color chart under my CRI 86 5000K fluorescents with one under a Cree WH and I couldn't tell the difference. That's where the CRI of 85 comes from. It's a guesstimate, but an educated one. Note that the Crees as a general rule seem to have a somewhat better color in the deep red area than other white LEDs I've seen. Others have noticed this as well. A warmer bin of a cool-white SSC might indeed only have a CRI of 78 or so.



> Second of all metal halide lamps and sodium vapor lamps differ dramatically in CRI, with high pressure sodium vapor lamps with CRIs between 22-75, and metal halide lamps with CRIs between 65-80, so differences in rendering are more likely due to CRI difference rather than strictly color temp. *while there is some overlap, there is no reason to suspect that your sodium vapor lamp fell at the very high end of CRI and your metal halide lamp fell at the very low end of the range*


NYC uses sodium vapor with a CRI of about 65. In parking lots usually the lower quality metal halide (CRI 65) is used, with the higher CRI lighting being usually used in sports stadiums. Therefore, the contrast difference is not from the metal halide having a better CRI.

It's already been widely documented that all other things being equal (intensity, CCT, beam pattern), lights with a CCT of around 4000K to 5000K offer best contrast under typical streetlighting conditions. Any higher or lower and contrast suffers. If I come across a link later I'll post it. Right now I'm a little pressed for time.


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## 2xTrinity (Jun 21, 2007)

jtr1962 said:


> Yes, I've felt that way as well, and my observations with metal halide versus sodium vapor streetlights have more or less confirmed these feelings. Both have a similar beam patterm. If indeed yellow light is better at penetrating fog, then the sodium vapor should win hands down. This is not the case. I've found that metal halide is just as good, even in cases where a lower wattage metal halide bulb was substituted for sodium vapor, meaning lower lux levels. Now if only I can convince the city to replace those awful sodium vapor lights with either metal halide or LED. For the last 35 or so years they have ruined the aesthetics of going out at night.


In situations with fog, I find that the biggest factor at play is the design of the fixture, not the lamp being used. Most of the sodium vapor lamps in my area tend to throw a lot of light out to the sides -- probably as a way of saving money by using fewer lamp posts further apart. The fact that sodium is so warm does mean the direct glare from these lamps is tolerable, but in fog, the lights are terrible, the bright amber glowing fog is far worse than having no lights. Using metal halide _in those fixtures_ would actually be worse in terms of glare and causing problems in fog, even though in general, metal halide performs much better.

The lights that perform best in the fog are the ones that direct light straight down, with no direct glare in the eyes of drivers. This is sort of like the difference between using your vehicle's low-beams vs. high-beams in the fog, even with identical bulbs the the low beams are better at penetrating fog. When facilities have switched from Sodium to Halide in those kinds of fixtures, I have noticed major improvements in visibility in just about every respect.


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## wrathothebunny (Jun 21, 2007)

JTR1962,

Crees highest quoted CRI measurements are 80 for their 7090s. If they were able to achieve higher, I'm sure they would have advertised this. The lamps that they have recently released specifically for outdoor lighting are labeled as having CRIs of 80s. There is no reason to suspect that Cree is undereporting their CRI figures. In any case, the cree that gets their CRI of 80 rating is in the 2600-3700 K CCT, which would roughly match incans CCT which I believe you said you do not like. The Cree in the 3700-5000 K CCT has a CRI of 75. The Cree in the 5000 K+ CCT doesn't have a CRI listed, but when you look at Cree's graph of the spectral values, you can see that it is the most skewed and uneven, and has the least red in the group. I would "guestimate" a CRI of 70, not 85. Here is a link to their product brochure.

http://www.cree.com/products/pdf/XLamp7090XR-E.pdf

I would also take exception to your statement that it has been "well documented" that the preferred color temp for street lighting conditions is 4000-5000 Kelvin. The 4000 K bit is correct, the 5000 K bit has not been substantiated in research. Perhaps if you had very bright street lighting, then maybe you could start to approach that, maybe. However, for all intents and purposes, the ideal color temp range is closer to 3000-4000 Kelvin for handheld, outdoor, flashlight use. Please refer to the following chart.







Concerning the impact of color temp - Sodium vapor lamps can have a CCT as low as 2250, obviously much lower than high quality xenon incans in the 3200-3300 K range. Sodium vapor lamps are also widely despised, and their spectral pattern of light emissions hardly seems natural. I think you raise an interesting point, however, I question to what degree we can generalize from your experience of sodium vapor lamps to metal halide lamps in relation to incans to LEDs. Here is some info that may identify spectral distribution as the culprit.

Here is a picture illustrating how High Pressure Sodium Vapor lamps appear to be the complete inverse of LEDs, with woefully deficient violets, blues, blue/greens, and rich greens.






Here is a picture illustrating how Metal Halide lamps appear to have a much better spectral distribution, covering violets, blues, greens, yellows, and reds.


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## racerx2oo3 (Jun 21, 2007)

*All things have there place...*

The question of CRI comes more into play in situations where color accuracy is a high requirement. As with all lighting technologies improvements in light quality tend to follow short distance behind innovation. This was also the case with the fluorescent light market. Low initial CRI on fluorescent lights gave them a bad rap and made the adoption rate much lower than would have been the case if they had a higher CRI value. However the problem there was the fact that household fluorescent lighting is a constant use application. No woman wants to try putting on makeup in a bathroom lit by fluorescent lighting when a low CRI value means that you literally cannot tell how your makeup will look under daylight or incan lighting. The market has addressed these needs and more and more fluorescent lighting is of the full spectrum (or fuller spectrum) variety. 

For flash lights, the fact that they are intermittent use devices reduces to a great extent the need for being able to render the full color spectrum. There is a greater need for LED's to render higher CRI levels in other industry applications (general lighting, automotive, etc.) 

In the majority of situations when a flashlight is used or needed, the need for 100% full spectrum rendition is not necessary, and is generally out weighed by the need for more light or light for longer periods of time. That is not to say that full spectrum LEDs would be a bad thing or are unnecessary, only that for the wide majority of applications color rendition is not a crucial necessity.

Sean


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## Archangel (Jun 21, 2007)

Where did you read that mesopic applies to dawn/dusk? I've never run across that. I don't see how even pre-dawn light levels can't exceed 3.4 cd/m2 (1 lux). You've obviously been to the point where you'd considered your eyes at least partially dark-adjusted and have noticed how little light is needed to knock you out of that state. 


wrathothebunny said:


> It may well be too encompassing, so I apologize for not being more precise. However, for most LED torches, the lumen output, I seriously doubt, would exceed dawn and dusk levels - and mesopic vision corresponds to dawn and dusk levels. A SureFire M6 with a 500 lumen high output bulb, well, that would be clearly photopic any way you look at it.


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## wrathothebunny (Jun 21, 2007)

Archangel said:


> Where did you read that mesotopic applies to dawn/dusk? I've never run across that. I don't see how even pre-dawn light levels can't exceed 3.4 cd/m2 (1 lux). You've obviously been to the point where you'd considered your eyes at least partially dark-adjusted and have noticed how little light is needed to knock you out of that state.



Several places, but I will refer you to literature from the US Army for their Aviators, where they identify mesopic response as such.

http://www.usarmyaviation.com/pubs/Miscellaneous/NIGHTSSTUDYGD.doc

[FONT=&quot]"Mesopic Vision[/FONT] [FONT=&quot]. Mesopic vision is experienced at dawn, at dusk, and during full moonlight. Vision is achieved by a combination of cones and rods. Visual acuity steadily decreases as available light decreases. Color perception changes because the cones become less effective. As cone sensitivity decreases, crew members should use off-center vision and proper scanning techniques to detect objects during low light levels."[/FONT]


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## jtr1962 (Jun 21, 2007)

wrathothebunny said:


> I am also curious how you were able to obtain such precise CRI estimates of the sorts of bulbs that your city is using.


I saw a couple of burned out bulbs in the street and looked it up. IIRC the term was brand was GE Lucolux and the CRI was in the 65 area. I also note that color rendering under these lights isn't as horrible as under the lights in the 1970s. The older lights made a red car look like black or brown.

Also, Cree may not underreport their CRI figures but by the same token they only report them for a "typical" bin. A warmer bin in the various ranges will probably do better while a cooler bin will do worse. I wish I had the equipment to analyze CRI so as to settle this once and for all. I don't think it's much of a stretch to say warmer bins can have CRIs in the mid 80s. I remember that Lamina ceramics has a 4300K part with an advertised CRI of 90. It probably uses something in addition to the usual YAG phosphor, but I think a regular white plus YAG phosphor LED with a CCT of 4300K would probably achieve a CRI in the mid-80s. BTW, in Cree's literature those are generalized graphs representative of the typical LED in that CCT range. The 5000K to 10000K graph is probably representative of a CCT of 6500K or 7000K, not 5000K. And I'll add that a lot of the CRI deficiency of white LEDs stems from their weakness in the yellow-green area more than in the reds. Fill that in and you'll probably get well into the 80s. From 650 to 700 nm I see pretty decent output. Granted, it falls off past 700 nm, but this is getting into a realm where human vision isn't particularly sensitive anyway.

Also, as others have said, CRI is not necessarily a good metric of the quality of a light source. I tend to find that gamut area agrees more with my own personal perceptions. Here is an article on that. Maybe that's why I like the Cree WH XR-E as much as my CRI 86 tubes even if it's CRI turns out to be in the 70s. Also note that incandescent doesn't do terribly well under the GA or FSI metrics. That explains why a number of people aren't that crazy about incandescent lighting despite the CRI of 100.


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## wrathothebunny (Jun 21, 2007)

JTR1962,

Refer back to my original post, I was editing it to remove some poorly worded information, as well as to insert some new stuff too, so that may have changed from when you quoted from or referred to it. 

Concerning the 5000 K Cree bit, Cree specifically states that their 3700-5000 K Cree achieves a lower CRI of 75 compared to its warmer CCT counterpart. The trend in their product literature seems to indicate that as CCT increases for their LEDs, CRI decreases, with the warmest LEDs having a CRI of 80, and the coolest likely having the lowest CRI, though they will not state what that is. To claim that the natural variance in Cree's manufacturing may yield even warmer LEDs than that which their 80 CRI figure is meant to apply (perhaps falling at 2600 K), and that such very warm chips may have CRIs greater than 80, well, I suppose its possible. However, claiming so would be premature, and how would this even apply to most users? In any case, your super-warm Cree would have a CCT closer to 2600 K, and I believe you mention that you prefer 4000 K+ color temps. At this point, you would be better going with a high-pressure Xenon incan for CCT.

Also, to address your posted article, CRI is a flawed, I agree, indicator of color rendering. However, it currently is the only internationally agreed upon standard to date, and so that is what we live with. Individual analyses of each light's unique spectral qualities can help to make up for this when CRI figures fail to tell the whole story. There are several competing color index rating scales that are seeking to replace CRI as the index by which we judge the color rendering properties of light. It will be interesting to see which wins out, but currently none have achieved international acceptance to replace CRI. By the way, I hope you realize that the LED figures in that link refer to RGB arrays, not "white" LEDs - I have previously discussed how RGB LED arrays can get past the color rendering deficiencies of white LEDs, in fact, Philips is currently making some for accent lighting and they should look quite nice.


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## mchlwise (Jun 21, 2007)

wrathothebunny said:


> Mchlwise,
> Weren't you going to offer some empirical contribution or something?



No. 



wrathothebunny said:


> ...otherwise you're just flapping your trap.



Who's the one just flapping his trap!? 

Here's another pearl of wisdom from someone who knows far more than you, requoted for truth:



LuxLuthor said:


> ...I think this thread is mostly about Wrath enjoying practicing his debating skills..



You think you can debate, you think you can come in an "win" with "truth and logic", you think you can "prove" your point, and you don't listen to what anyone says other than to try to prove that they're wrong and you're right. 

There's been plenty of "emperical contributions" as well as people pointing out the flaws in your tactics (to say nothing of the flaws in your arguments) and others trying to help you understand how you can make a decent argument without coming across as a jerk. 

You've pretty much ignored all of it. 

Here's another post that should have been VERY enlightening to you, but I'm sure you unfortunately won't relize the truth of it until years from now when you're a little older and a lot more mature:



Empath said:


> ...this isn't anywhere near as important as it feels to you.




Oh, in case you misunderstood, he's talking about this thread. :sick2:


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## MarNav1 (Jun 21, 2007)

I haven't met any incan hater's per se, but my first experience with them was a Surefire G2 and the lamps(in my experience) were VERY fragile and it ate batteries at a fast clip too. So this is the main reason why I favored LED lights. I didn't even consider buying another until the excellent review
(I forgot who wrote it now) on the A2. Incans do have advantages in some areas and Led's in others. For me since I don't live around a wooded area or walk trails an Led light will always be my first choice. But I have an A2 just in case. Oh and please lets not get into the P60 bulbs being fragile or not, I'm talking my experience only.


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## Archangel (Jun 21, 2007)

I guess by "dawn" they mean "nautical twilight", because there's no way that civil twilight is mesopic if the full moon is.


wrathothebunny said:


> [FONT=&quot]"Mesopic Vision[/FONT] [/SIZE][FONT=&quot]. Mesopic vision is experienced at dawn, at dusk, and during full moonlight. Vision is achieved by a combination of cones and rods. Visual acuity steadily decreases as available light decreases. Color perception changes because the cones become less effective. As cone sensitivity decreases, crew members should use off-center vision and proper scanning techniques to detect objects during low light levels."[/FONT]


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## BB (Jun 21, 2007)

I started this message a bit ago--but most of the information is still relevant to the current conversations in this thread...



wrathothebunny said:


> ...hell, even moonlight allow you to see colors, then when would you submit the scotopic curve comes into effect?...



Yes, I would agree with that... I like Soffiler's link much better than your picture of scotopic vs photopic sensitivities because your graph normalizes both to 100%.

Soffiler's link (second "article" down) shows that the relative sensitivities are much different between rod and cones (as one would suspect)... At relative peak wave lengths, the difference (in terms of defining lumen as a mechanical measurement of human eyes) is 1700 lumen/watt vs 683 lumen/watt or about a 4 db difference (~2.5:1 ratio).

And I am surprised that 4db is the difference--I would have expected it to be much more.

Regarding the Moon and scotopic vision--from this short blub:



> The scotopic sensitivity function describes the response of the human visual system to luminances corresponding to scotopic adaptation. The upper limit for scotopic adaptation has been changing over recent years, with the older value of 0.034 cd/m2 dropping to 0.001 cd/m2. In any case, the level of brightness under full moonlight may be considered an approximation of the upper limit of scotopic adaptation. Scotopic sensitivity applies under very low light conditions, when the only photoreceptors responding are rods, so there is no color perception.



And here:



> These CIE sensitivity functions are considered valid when the visual system is mediating photopic luminances, defined as occurring at or above 3.4 cd/m2. At lower luminances, the sensitivity of the visual system changes and the visual system is described as being in a state of "mesopic" adaptation.



So the range between "full color" vs true night vision is, roughly at a minimum, 3.4/0.001 or ~35 db... Following the "mesopic" link above takes you to a short discussion about light levels between moon light, local, and main road lighting... Gives you an idea of how much light even "minimal" artificial lighting is... Basically 10-20+ db (10-100x +) that of moon light.

So--going backwards, to the original point (if there was any)--using virtually any flashlight (other than specialized red or very very dim lights) takes us fully into the photopic zone.

The last issue is the eye's ability to see contrasts... A bright object in the flashlight beam is going to overwhelm the eye's ability to see the dark object behind (and wash out any "night vision")... Here is a neat link that attempts to compare the eye to camera specs... From the link:



> The Human eye is able to function in bright sunlight and view faint starlight, a range of more than 10 million to one. But this is like saying a camera can function over a similar range by adjusting the ISO speed, aperture and exposure time.
> 
> 
> In any one view, the eye eye can see over a 10,000 range in contrast detection, but it depends on the scene brightness, with the range decreasing with lower contrast targets. The eye is a contrast detector, not an absolute detector like the sensor in a digital camera, thus the distinction. (See Figure 2.6 in Clark, 1990; Blackwell, 1946, and references therein). The range of the human eye is greater than any film or consumer digital camera.



So, while our eyes can operate in a range of 10,000,000:1 (70 db), in reality our contrast limits to ~10,000:1 (40 db). A typical LCD TV contrast range is about 400-500:1 (27 db)...

The amount of light, spectrum of the light, reflectivity/color/contrast/geometry/etc. of object in scene, dynamic range of the scene, etc. all affect our ability to identify any particular scene.

Now, what was the original point(s) of this thread? :thinking:

-Bill


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## wrathothebunny (Jun 21, 2007)

BB,

This is all very interesting information, and it may take me some time to get through it. However, I would like to state that the idea of pure categories of scotopic, mesopic, and photopic visual processing seems erroneous to me, as vision operates along a continuum, as do most processes, and there is likely a mixture of each. I highly doubt that each of these categories truly "carve nature at its joint." In any case, rather than sounding like a bunch of theologeons arguing about how many angels can fit on the head of a pin, why doesn't somebody take a red led light outside at night, and a blue led light, and see which illuminates better? From what I gather, it should be the blue light, but test it out and see if I'm wrong.


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## jtr1962 (Jun 21, 2007)

wrathothebunny said:


> Concerning the 5000 K Cree bit, Cree specifically states that their 3700-5000 K Cree achieves a LOWER CRI of 75 compared to its warmer CCT counterpart. The trend in their product literature seems to indicate that as CCT increases for their LEDs, CRI decreases, with the warmest LEDs having a CRI of 80, and the coolest likely having the lowest CRI, though they will not state what that is.


Putting aside what Cree's literature states, I've seen Nichia for example advertise CRIs as high as 85 for their regular white LEDs. Also, in the article I linked to they had some charts on page 2 where the tested CRI of white blue plus YAG phosphor LEDs is in the high 70s to low 80s. I've also seen similar results in other independent testing (high 70s to low 80s). They don't state the CCT of the LEDs although 6500K is usually typical. Now if I were an LED manufacturer, given the wide variability in tints, spectrums, etc., I might likely put the worst case CRI for a given CCT in my literature rather than the typical or best case just to avoid being sued for false advertising. Maybe this is why Cree's figures are suspiciously low compared to other manufacturers? And this despite the fact that many here agree that for a given CCT Crees seem to have a slight edge in color rendering.

Look at this chart NewBie posted a while back:

http://www.molalla.net/~leeper/seoulxre.png

The Cree WC is a much cooler bin than the SSC SXO yet it still has superior relative output above 620 nm. A WH bin would do far better. SSC actually advertises their "typical" 6500K P4 LED as having a typical CRI of 70 (minimum 65) here. It follows that the warmer SXO part would be better, perhaps in the mid to upper 70s, and a Cree part with a similar CCT better still owing to the higher relative amounts of red in the spectrum. I _still_ don't feel my guestimate of 85 is horribly off given all this. Even if it was, subjectively a Cree WH looks as nice as high-end CRI 86 T8 tubes. Not quite in the league of my full-spectrum CRI 91 tubes, but very close nonetheless. Fill in the mid-greens/very deep reds, and my guess is we would have a CRI well into the 90s.

P.S. Yes, I did reread your edited post, and it offers some nice info on HPS versus MH. We can all agree HPS is horrible. Incandescent isn't anywhere near as bad, although I really find household incandescent to be seriously deficient in blues (3200K flashlight bulbs are much better).


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## 2xTrinity (Jun 21, 2007)

> Concerning the 5000 K Cree bit, Cree specifically states that their 3700-5000 K Cree achieves a lower CRI of 75 compared to its warmer CCT counterpart. The trend in their product literature seems to indicate that as CCT increases for their LEDs, CRI decreases, with the warmest LEDs having a CRI of 80, and the coolest likely having the lowest CRI, though they will not state what that is. To claim that the natural variance in Cree's manufacturing may yield even warmer LEDs than that which their 80 CRI figure is meant to apply (perhaps falling at 2600 K), and that such very warm chips may have CRIs greater than 80, well, I suppose its possible. However, claiming so would be premature, and how would this even apply to most users? In any case, your super-warm Cree would have a CCT closer to 2600 K, and I believe you mention that you prefer 4000 K+ color temps. At this point, you would be better going with a high-pressure Xenon incan for CCT.


IMHO what is actually happening is that the WH Cree in reality does probably have a fairly low CRI, however all CRI really tells is the root-mean-square difference betweeen some arbitrary test colors under the light being tested, and a blackbody source. The Cree could be dead on perfect on most, but way off on a deep red shade -- since the CRI number is root mean sqaure, one color being way off will lead to a big drop in the CRI number. An array of WH Crees + a separate red emitter under a diffuser however I believe could certainly exceed 90 CRI, the only thing missing is deep red (I'm so geeky I've actaully used a CD as a diffraction grating to look at the spectrum of my LED flashlights...)

In the case of the comparison between the Cree WH and the 5000K 86CRI fluorescent, I find that fluorescent is slightly more accurate, especailly in distinguishing colors as the extremes of the visual spectrum -- deep red, and deep blue/violet. However, the WH Cree provides more saturated yellow/greens, which tends to look more pleasant. CRI only tells how much a light source differs from blackbody, not how it differs. Two lights with hte same CRI and same color temp might be dramatically different -- I've certainly found that to be true when comparing different brands of 82 CRI CFLs.


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## knot (Jun 21, 2007)

*Re: All things have there place...*



racerx2oo3 said:


> The question of CRI comes more into play in situations where color accuracy is a high requirement. As with all lighting technologies improvements in light quality tend to follow short distance behind innovation. This was also the case with the fluorescent light market. Low initial CRI on fluorescent lights gave them a bad rap and made the adoption rate much lower than would have been the case if they had a higher CRI value. However the problem there was the fact that household fluorescent lighting is a constant use application. No woman wants to try putting on makeup in a bathroom lit by fluorescent lighting when a low CRI value means that you literally cannot tell how your makeup will look under daylight or incan lighting. The market has addressed these needs and more and more fluorescent lighting is of the full spectrum (or fuller spectrum) variety.
> 
> For flash lights, the fact that they are intermittent use devices reduces to a great extent the need for being able to render the full color spectrum. There is a greater need for LED's to render higher CRI levels in other industry applications (general lighting, automotive, etc.)
> 
> ...



QFT


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## Aircraft800 (Jun 21, 2007)

There is a lot of technical stuff here I don't understand yet (soon), but I have both.

I like my LED for inside, close up work, where size, and long run time matter. It gives a very white, clean, lite not like the original LED's that tended to turn everything blue. 

I use my Inca for outside work where color and Throw matter, I don't need more than 70 min. run, or so, here.

Does the new generation LED's have the throw that a 700+ lumen inca can? Maybe there is now, but a few years back there was not.

One other consideration that it looks like no one is addressing, the initial cost of a quality LED. I don't think most people have >$300 to spend on a ShureFire, but a Mag85 build here could be $165 or so. I'm pricing a LED build myself, so I've got a lot to learn.


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## jtr1962 (Jun 21, 2007)

2xTrinity said:


> However, the WH Cree provides more saturated yellow/greens, which tends to look more pleasant.


That's probably where the gamut area and/or full-spectral indices would come into play. I'd bet that one or both of these are better for the Cree. I suspect the Cree appears more pleasant because it is a more continuous spectrum than a spiky triphosphor fluorescent.

The Crees seem to not have the sharp mid-green deficiency of other cool-white LEDs, basically only lacking in deep reds. Perhaps one 660 nm red 5mm per Cree might take care of that.


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## wrathothebunny (Jun 21, 2007)

BB,

I am having a very difficult time finding definitive information concerning the upper boundaries of mesopic vision, though the lower boundaries seem pretty well defined. Here is what I have learned. The lower boundary of mesopic vision, which is shared by the upper boundary of scotopic vision, is demarcated by the lowest sensitivity of cones in the eyes. Dim starlight would be below this threshold, moonlight above it. The upper boundary of mesopic vision, however, appears to be more a function of how useful the rods are in relation to the cones for visual perception. When rods receive too much light, they bleach and provide basically no information, but I cannot find a figure for when this happens. I suspect, again, that the variation in rod use to cone use exists on a continuum, with some high illuminance value corresponding to complete bleaching (I know not what). _*Edit - The upper boundary of mesopic vision has been sometimes classified as 3.4 candles per square meter, however, they also mention that street lighting tends to fall below this threshold. I am not yet convinced that this threshold is absolute and corresponds to bleaching of the rods. There are other issues at play that come to mind as to whether or not handheld flashlight use at night falls within the mesopic range. For one, the luminance values given for the mesopic boundaries are for ambient light. Flashlights do not produce ambient light, but focused light. So, on the periphery you could have pitch darkness, while the center would be illuminated by the flashlight. Some issues that might impact how the eyes respond to focused and partial flashlight illumination could include: how quickly the eye returns to night-adapted vision following exposure to mild light; how the eye scans its environment and how long it rests on the illuminated area provided by the flashlight;how bright the spill of the flashlights are and how important this is compared to their hotspots. Again, there are a lot of issues at play here, but common sense seems to suggest that night-adapted mesopic vision occurs, well, at night even if you have a flashlight for common usage. So, again, I think a real world test would be in order.*_

Nonetheless, mesopic vision is characterized as using both rods and cones to perceive the environment. I find it very difficult to believe that this does not happen at night with use of a flashlight. Again, this seems to be very tricky to pin down precisely, and I suggest testing this hypothesis in vivo outdoors at night with red and blue LEDs.


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## Outdoors Fanatic (Jun 21, 2007)

Great post wrathothebunny!!:twothumbs

I agree 110% with you! Incan is just better for the outdoors, there is no comparison. LEDs are great indoors, but when you need some serious light capable of penetrating fog, to overcome ambient light, to render colors accurately or just reaching out and touch someone. Then you need an incandescent!
:nana:


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## WadeF (Jun 21, 2007)

Outdoors Fanatic said:


> LEDs are great indoors


 
Yeah, my LED's are pretty useless outdoors, I can only light up my backyard, a building 100 feet away, a tree over 200 feet away, etc. 

The other night night I was outside talking to my neighbor and we smelled something from another neighbor's yard (smoke), which was in total darkness, so I pulled out my Fenix PD2 Q2, set it to Turbo, and hit their yard which was about 80-100 feet away. I had to quick pull the light away because it blasted their yard with light and looked like some kind of swat team was raiding it. I was afraid they'd be like "WTF was that?!"  

All that from something about the size of a lipstick an a single CR123 battery.


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## Outdoors Fanatic (Jun 21, 2007)

WadeF said:


> Yeah, my LED's are pretty useless outdoors, I can only light up my backyard, a building 100 feet away, a tree over 200 feet away, etc.
> 
> The other night night I was outside talking to my neighbor and we smelled something from another neighbor's yard (smoke), which was in total darkness, so I pulled out my Fenix PD2 Q2, set it to Turbo, and hit their yard which was about 80-100 feet away. I had to quick pull the light away because it blasted their yard with light and looked like some kind of swat team was raiding it. I was afraid they'd be like "WTF was that?!"
> 
> All that from something about the size of a lipstick an a single CR123 battery.





> I can only light up my backyard, a building 100 feet away, a tree over 200 feet away, etc.



...And make everything look like a bad horror movie from the 50's. Pale, fake and two dimensional.


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## wrathothebunny (Jun 21, 2007)

Mchlwise,

You have repeatedly posted your personal insults to me on this thread. These insults do not occur in the context of an overall discussion or debate between me and you on the issues, you simply poke your head in every now and then to express your contempt for me. By any definition, this is flaming and against CPF rules. I am wearing thin on my tolerance for you, and any further flames from you will result in me reporting you to the administrators of CPF to consider disciplinary actions against you up to and including banning you from this online community.


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## BB (Jun 21, 2007)

wrathothebunny said:


> Nonetheless, mesopic vision is characterized as using both rods and cones to perceive the environment. I find it very difficult to believe that this does not happen at night with use of a flashlight. Again, this seems to be very tricky to pin down precisely, and I suggest testing this hypothesis in vivo outdoors at night with red and blue LEDs.



Basically, if we believe the charts--you will not see anything with the red light until you "see red".

With the blue, you will see "black and white" with the light source quite low (rods), until you see the color blue (cones).

So, what is the exact question you are asking? At what levels of absolute c/m^2 you can discern an outline between contrasting objects? Or are you asking at what level you can identify a green vs brown vs read object?

And, again, what is the desired result of this test? Is it preservation of night vision, ability to shoot a varmint and not shoot (God forbid) a child? Monochromatic light is by definition not going to be a good general purpose light in any case.

If you read through the link I suggested above, you will find a chart listing c/m^2 illumination levels of a generic parking lot / road (moon light, minor road, brightly lite main route). The ranges within a particular lighting scene (moon, minor road, major road) are, roughly 10:1 in range (example: dark to light area under moon) and with respect to each other, the minor road is, roughly 10x as bright as a moon lite road, and a brightly lite road is 10x as bright as a minor road.

So, from deep moon to a bright lot, we are talking about a a 0.001 to 10.0 (candela per sq meter / lux in this chart) range... This would be the same as comparing a 1 watt lamp with a 10,000 watt lamp. Duh--the dynamic range differences are so large with respect to night time lighting scenes that trying to generalize any better/worst flashlight technology is virtually worthless and will end up with a bunch of people arguing past each other.

If we are trying to create some other generalizations about "good vs bad" illumination options--I fell across this link. And, while it does not address filament vs LED--it does a very good job of summarizing several issues. And it does it with a very objective measurable human characteristic--reaction time. On one end is Good vs Poor color rendering (Metal Halide--pretty white light. Vs Low Pressure Sodium--that very monochromatic "orangish" light). And like any good link intended to close the door on circular arguments (yea--like that is going to happen here), it also include another axis--light intensity. So, what does it find?



> Reaction time is the period between the presentation of a stimulus and the response from the subject.
> 
> In recent years different lighting researchers have reported studies of reaction time for peripheral mesopic stimuli presented during different simulations of driving. Results have consistently shown that sources with SPD's with more short wave radiation have shorter reaction times for these simulations.
> 
> ...




I think that this is the "killer link" to "re-"frame (I hope) this discussion... Above, roughly 3 lux and above (or a very well lite road/parking lot), the color of the light source (say CRI for simplicity of discussion) does not matter. All three types of light sources (Metal Halide, HPS, LPS) give the same human reaction time (~600 milliseconds).

When you drop the light levels to that of 0.1 lux (poorly lite road, still 10x brighter than moon lite), you see reaction times of MH light rise to 0.8 seconds, while the monochromatic lamp (LPS) is 1.2 seconds. HPS, a bit nicer light, but nowhere near white is about 1.15 seconds of reaction time.

What does this tell me--bright lights of any color will work pretty well. In dimmer light (still brighter than full moon), any "white lamp" is quite a bit better than any monochrome light. LED or filament probably does not matter whole lot at this lighting level (in terms of human reaction time).

Once light falls to scotopic levels (following is an assumption on my part--have not found an equivalent reaction time chart for these lighting levels)--then you are talking about Rods only... Then monochrome vs high CRI does not matter--cones are not activated and it is simply c/m^2 light level and sensitivity of rods at that color.

If light levels are sufficient to activate the Cones--then anything that looks reasonably white is probably going to give close to equivalent reaction times.

There are so many other interesting physical aspects with our eyes that trying generalize further is not going to be very fruitful. 

We can start a new thread discussing what the heck Retinal Ganglion Cells have to do with regulating our vision--they are very sensitive to deep blue light--but don't affect visual recognition, what gives? (and, of course, differences among people).

-Bill


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## wrathothebunny (Jun 21, 2007)

BB,

The information you are presenting is interesting and comprehensive. However, I do not believe that the research you have presented on reaction time has any bearing on contrast rendition in the environment, otherwise a light-source, say with only two spikes in the blues and yellows, completely lacking in everything else (that provides sufficient lux to quickly react to environmental stimuli) would yield good contrast? In any case, you seem to present the idea that the human visual system is not capable of extraordinary contrast perception. Nothing could be further from the truth. The eyes do not just take in your whole field of vision and then process it, like some sort of camera. They rapidly move across your field of view, pausing in some places, jumping at others, recalibrating throughout the whole process. So your eyes can look over a scene with vastly varying illumination levels, and still render it better than any film camera or digital camera modern technology can yet produce. Think of this, your eyes can go from rendering the yellow of the noon sun out your window to the red of your indoor rug in what almost amounts to an instant.

In any case, you asked what the point of all this was. This all launched from an assertion that I made that the lack of red in typical white LED spectrums was further compounded by the lesser sensitivity of vision to red at night (whereas incan has plenty of red output). Whether or not the eyes are less sensitive to red at night, with flashlight use, is determined by whether or not mesopic vision comes in to play. If it turns out it does come in to play, then that would validate my assertion, if it does not come in to play, then it would invalidate my assertion, and there would be only the main effect of low red spectral color in white LED light without any further compounding (still bad, just not as bad).


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## 2xTrinity (Jun 21, 2007)

> In any case, rather than sounding like a bunch of theologeons arguing about how many angels can fit on the head of a pin, why doesn't somebody take a red led light outside at night, and a blue led light, and see which illuminates better? From what I gather, it should be the blue light, but test it out and see if I'm wrong.


I have a mouse that has a little blue LED on it. In the dark, when my eyes are dark adapted (takes about 10 minutes in the dark undisturbed before I reach this point), the tiny blue LED provides enough illumination for me to navigate clearly in the adjacent hallway, and in several adjacent rooms -- essentially it lights up my whole upstairs, but it all looks black-and-white (this is the rods, pure scoptopic vision). The red LED, which is much, much brighter, is far less effective as a ceiling-bounce light. I can see clearly with the red _only_ by direct illumination, and it causes a distinct "tunnel vision" effect compared to using any other color LED (only the cones can see it, and it doesn't stimulate the rods at all, pure photopic vision). The most useful single color LED, if i don't care about preserving my night vision, is green -- I can see much more clearly in the dark with green light than with any other single-color LED by far. Blue, and especially red, make fine print look blurry, while it looks crisp with green light. I believe the reason I prefer 4000K/neutral white for reading lights, because that is where the green component is strongest, relative to the other colors.


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## wrathothebunny (Jun 21, 2007)

Thanks 2xTrinity! Can we replicate this with higher illuminance levels anyone?


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## mchlwise (Jun 21, 2007)

wrathothebunny said:


> Mchlwise,
> 
> You have repeatedly posted your personal insults to me on this thread. These insults do not occur in the context of an overall discussion or debate between me and you on the issues, you simply poke your head in every now and then to express your contempt for me. By any definition, this is flaming and against CPF rules. I am wearing thin on my tolerance for you, and any further flames from you will result in me reporting you to the administrators of CPF to consider disciplinary actions against you up to and including banning you from this online community.


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## wrathothebunny (Jun 21, 2007)

Well everyone, that seems to about sum up Mchlwise's respect for the rules here at CPF, lucky for him a laughing icon can't be considered a flame. Has anyone else here had any run-ins with this guy?


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## BB (Jun 21, 2007)

wrathothebunny said:


> BB,
> _*a)*_... However, I do not believe that the research you have presented on reaction time has any bearing on contrast and detail rendition in the environment, otherwise pure blue light, pure green light, etc. would provide sufficient lux to quickly react to environmental stimuli, but what would the contrast be?
> 
> _*b)*_In any case, you seem to present the idea that the human visual system is not capable of extraordinary contrast perception. Nothing could be further from the truth. The eyes do not just take in your whole field of vision and then process it, like some sort of camera...



Regarding _*a)*_, I did give research used to design road lighting and by governments to set speed limits and reaction times based on three points of an analog to the CRI scale (MH vs LPS). So, what is the problem?

Do you want to argue that a highway guy wearing an orange vest will probably blend into the background when using any monochromatic light source--I would never be so stupid to argue against that. My Dad had a friend 4 decades ago _*who*_ complained about the highway workers who wore "camouflage clothing" after he almost hit a guy (turned out to be an example of male Red/Green color blindness _*as the guy was wearing the standard florescent orange safety vest of the day*_).

This slice of data was intended to show that there is a measurable physiological component that can be graphed between good CRI, poor CRI, and lighting levels. And from this graph, at a physiological level, that above ~3 lux, there is hardly any difference between a Filament Bulb and a good CRI LED.

Not to say that there is no difference--just that the differences are now on biased to second order effects (color/contrast of illuminated objects and personal biases to various sources of the light).

Regarding _*b)*_, where the heck did that come from?

I gave the actual numbers for the ability of human eyes to operate in a very wide dynamic range... And even offered some real numbers and examples of what those ranges are in real life.

Did you even read my pull quote from my 12:32 post today where I said here is an interesting link that (in my words) "(h)ere is a neat link that attempts to compare the eye to camera specs"?



> In any one view, the eye eye can see over a 10,000 range in contrast detection, but it depends on the scene brightness, with the range decreasing with lower contrast targets. The eye is a contrast detector, not an absolute detector like the sensor in a digital camera, thus the distinction. (See Figure 2.6 in Clark, 1990; Blackwell, 1946, and references therein). The range of the human eye is greater than any film or consumer digital camera.


Human eyes (and hearing too) is an amazingly complex signal acquisition and processing environment. Even today, we are just beginning to understand all of the things, we do without any conscious thought, our "wet-ware" does.

-Bill :candle:


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## wrathothebunny (Jun 21, 2007)

Sorry BB, it looks like I misread your post. I'll take another look at it. Concerning your first point, that's why I edited my original argument to address lower spectral quality than simply monochromatic light, as I realized after writing it that it might not address your post. Sorry about the late edit on that. In any case, reaction time does not directly relate to contrast. Obviously, the better the contrast the better the reaction time, but after a certain point, I imagine you only need mediocre contrast to achieve good reaction time. Correct me if I'm wrong. I also was never making the argument that incans provided greater reaction time than LEDs, just greater contrast and depth rendering of outdoor, largely organic environments. By the way, I've added more info to that post you quoted from, so you might want to check back and take another look.

[Edit: BB, you have posted a wealth of information that I find very interesting, and I thank you for that. I want to be able to take the time and examine it as it deserves. Right now, I've got work I still have to finish up for the day, and I will be out of town this weekend. I will try to get through this material, and perhaps contribute some of my own Monday or Tuesday. Again, I think this debate we are having is beneficial, and I am always open to learning new things and reversing incorrect hypotheses. We'll see where this debate take us. Till then ]


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## WNG (Jun 21, 2007)

mchlwise said:


>




+1


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## wrathothebunny (Jun 21, 2007)

WNG,

I can't believe you are actually encouraging Mchlwise's behavior. If you want your online community to degenerate into a forum where people disrespect and flame each other, I guess that's up to you. Honestly, I have no idea if the administrators would act on such a complaint or not, but it is telling that Mchlwise hasn't posted another insult on this thread, so maybe something got through. I have no respect for people who encourage lame behavior like flaming. Sure we all lose our heads at times and let a little negative emotionality out, I'm just as guilty as anyone. But when a member here establishes a pattern of continually posting with the primary, I repeat, primary purpose of insulting a specific member of this community, then such behavior should not be tolerated by anyone, including yourself WNG.


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## WadeF (Jun 21, 2007)

Outdoors Fanatic said:


> ...And make everything look like a bad horror movie from the 50's. Pale, fake and two dimensional.


 
What's the last LED you tried? Something from a few years ago? Try a P2D with the Q2 bin LED, or Gene Malkoff's LED drop-in for a Maglite. I find incans make everything look yellow and overly warm. If the only way to get better color is to carry some huge light that sucks batteries to put out enough incan lumens to make something look closer to daylight, it's just not worth it to me. To me white's look whiter with an LED, and colors look fine.


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## 2xTrinity (Jun 21, 2007)

WadeF said:


> What's the last LED you tried? Something from a few years ago? Try a P2D with the Q2 bin LED, or Gene Malkoff's LED drop-in for a Maglite. I find incans make everything look yellow and overly warm. If the only way to get better color is to carry some huge light that sucks batteries to put out enough incan lumens to make something look closer to daylight, it's just not worth it to me. To me white's look whiter with an LED, and colors look fine.


There is a third option -- 4200K HID. More overall output than incandescent, higher efficiency than LEDs, color is the best of both worlds.


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## dano (Jun 21, 2007)

Baiting, flaming, etc, are NOT tolerated. 

There's two members, in particular, in this thread that are taking jabs at each other. Any more of that behavior and it will be dealt with. This is not the place to have a personal debate.

Stay on topic....


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## BB (Jun 21, 2007)

wrathothebunny said:


> ...In any case, reaction time does not directly relate to contrast. Obviously, the better the contrast the better the reaction time, but after a certain point, I imagine you only need mediocre contrast to achieve good reaction time. Correct me if I'm wrong. I also was never making the argument that incans provided greater reaction time than LEDs, just greater contrast and depth rendering of outdoor, largely organic environments.



I was trying to take the "conscious thought process" out of the discussion (difficult to quantify, variable results based on same inputs) by using reaction time--which includes a good bit of "in-line" processing and little else.

If providing better contrast and depth rendering is not important to visual acuity--then reaction time would not have changed with respect to light levels and "colors" of lights used.

Obviously, lighting studies of roads and parking lots are "outdoors" -- but include other non-organic objects (cars and roads).

I thought that the study's results showing that reaction time was a function of "CRI" and intensity was a very interesting finding. You now have very specific lux points at which there are quantifiable outcomes based on lamp types and intensity.

If you involve conscious thought--then you might as well start pulling out a Pantone pallet, some sample test cards and start testing under LED, filament, and other lights--all the while varying intensity, current, voltage, etc.. I am sure that you will find a wide variation of results. And I would not be surprised to find that varying the current through a halogen lamp vs non-halogen will affect the test results just about as much as comparing between halogen, non-halogen and LED's.

But, what is the point in this discussion. Humans evolved on an earth light by the sun, with varying color temperatures, light levels, and weather conditions. There is no fixed ideal in nature. Our eyes are organic sensors with a pretty good range and auto-white balancing. Obviously, LEDs (and other light sources) are not the lighting that humans evolved under. But even "natural light" has huge variations... I am not going to rant on full sun, deep shade, north facing skylight or I quit. I make due with the best available solution and go on with life.

I keep coming back to your first quote and opening line:



wrathothebunny said:


> Ok, I just want to clear this up once and for all - quality of light matters! Have you guys ever heard of the 4 C's of diamonds: cut, color, clarity, and carat weight? The first 3 address quality, and the last addresses quantity. Sometimes, one gets the impression that the only thing that matters to the LED fanatics on these forums is quantity - meaning lumens and runtime. Lumens and runtime have NOTHING to do with the QUALITY of the beam, though everything to do with the QUANTITY of the beam. Both, of course, are important. So......let me remind you of some factors that influence beam quality, and why they matter....



"Quantity" of light goes hand in glove with "Quality of Beam" human perception... If you don't have enough Quantity, Quality does not matter. If you have a lot of Quantity, Quality matters a bit less (if you are looking to react to objects in your environment--per the posted study).

And Time not having anything to do with Quality of Beam?--Flashbulbs can have great CRI and an even beam/flood--but they certainly are not very useful as flashlights. 20 mseconds of a great beam and the rest of the time zero beam is "poor quality" for a multipurpose flashlight.

There are just so many straw men here--people replying to the opening post first have to correct inaccurate summarization of their statements (that many folks here have never made) and then they have to defend their corrections of their own statements. Then when try to bring the discussion to some point--off we go into the field elsewhere.

If the point of the discussion is that filament bulbs have a place in life--sure--nobody here denies that.

However, there are many very clear criteria for personal carry lights where LED's have improved many of the weaknesses of incandescent lights (high power, high temperatures, variable color temperatures when run at variable power levels, fragility, narrow operating range, short life to catastrophic failure, more battery for "same light", etc.). Focusing on one factor "such as lack of red" to the exclusion of all others when determining which flashlight(s) meets our needs best--that is just not practical... I am not going to (anymore ) bring around a 12 volt halogen spot light with a lead acid battery battery pack just to get the best CRI I can on a several hour walk.

But I am finding it difficult ignore straw men such as "...stop with all the "Incan is dead," or "I see no point to use (such an such an incan) when there is (such an such a "better" LED)"... when none of us have said that.

And, over the last few years, better LED's have given other light engines a run for their money (not just filament, florescent lanterns, even the old Coleman Gas Lanterns, pushing HID out of low end lights). Just like better incandescents and batteries pushed out carbide lamps out of mining (I think there are still "cavers" today that argue light quality between filament and carbide lamps).

And not too many years ago, there were no white LED's--and when white LED's became available--folks were overdriving them (at a detriment of phosphor/encapsulatment life to that not much better than a filament bulb) just to get the first really useful LED lights out there.

Right now the only folks that are trying to kill incandescents are our lawmakers... Nobody here wants to outlaw them.

But people are voting with their feet (and their wallets). What will it be like next few years--haven't a clue.

-Bill


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## wrathothebunny (Jun 21, 2007)

BB,

You clearly have a fascinating intellect, and I look forward to continuing this conversation with you. I started out this thread speaking from what I felt comfortable with as a solid base of knowledge. As you have brought new information and perspective to this debate, I find that in order for me to adequately respond to your points, I need to expand my knowledge a bit. I wish to address your points, and do so fairly. I don't have the time today to go that in depth, and I will be gone this weekend. However, please do not take my temporary silence on this matter as a consent to your points. I will respond Monday or Tuesday to continue this debate. Till then, thank you for your insights, and I appreciate your engaging in this discussion with me on logical and rational grounds.


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## Icebreak (Jun 21, 2007)

wrathofthebunny -

Your posts seem to indicate that an impressive amount of detailed research has been done regarding the color of light and how it effects vision. I would like to entertain your opinions on how different colors of light effect vision in some specific scenarios.

1) Environment: Fair to poor office lighting.

Would light from a blue LED peaking near 470 nm help or hinder in reading small print?

2) Environment: Low ambient lighting during a stage presentation such as a play.

Would light from red LEDs peaking near 625 nm spotting the target character help or hinder in defining the image of the target character?

3) Environment: Woods/Forest at night, clear sky, away from population and no moon.

Would light from a cyan LED peaking near 505 nm help or hinder vision in the area of defining the target image?

4) Environment: Woods/Forest at night, clear sky, away from population and no moon.

Would light from a royal blue LED peaking near 455 nm help or hinder vision in the area of defining the target image?

5) Environment: Low ambient lighting during a stage presentation such as a play.

Which of these colors of light would be easiest to hide from the audience on non-target backgrounds; blue 470 nm, red 625 nm, cyan 505 nm or royal blue 455 nm?

6) Environment: Medical diagnosis.

Which color of light would be best for diagnosing subdermal vascular anomalies; blue 470 nm, red 625 nm, cyan 505 nm or royal blue 455 nm?


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## BB (Jun 21, 2007)

wrathothebunny said:


> ...please do not take my temporary silence on this matter as a consent to your points...



I would not dream of it... Just have some fun this weekend and relax a bit--if you get a chance.

-Bill :wave:
PS: (I would humbly suggest just  'ing some of the posts and not to worry about those discussion stubs again--helps everyone stay on-thread).


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## wrathothebunny (Jun 21, 2007)

BB,

Thanks, till after the weekend then 

Icebreak,

What do I look like, a visual processing cognitive science researcher? You could ask a professor who has been teaching and researching visual processing phenomenon for decades and they still might not know the answers to those questions. I claimed to know that a substantial research body on the physiological and cognitive processes relating to vision exists. I did not claim that I happen to have knowledge of that entire research body, however.


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## molite (Jun 22, 2007)

Flashlights are like golf clubs there is not one out there that is perfect for every task.
My putter would be my EDC LED's.
My chipper would be my high power LED's
My irons are my hi power incans.
My big bertha driver is my HID's.

We could argue all day about what's better, a fork or a spoon? And I would ask are we having steak or soup?

Never the less with the leaps LED's are taking who knows, there could be a 5000 lumen LED in 2 years.
But as long as batteries are improving the incans will keep up.

I had to put in my "lo-tech" 2 cents on the great thread.

oh yea, to what Luxluthor said, I agree that night life doesn't begin till 700 lumens!!!


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## TigerhawkT3 (Jun 22, 2007)

2xTrinity said:


> There is a third option -- 4200K HID. More overall output than incandescent, higher efficiency than LEDs, color is the best of both worlds.


What I've seen of HID (i.e. metal halide) is pretty awesome, with the output and interesting purplish tint, but I don't have any HIDs for several reasons: They're expensive, the bulbs are expensive, they have a slow startup/restrike time, and they get less and less efficient as you decrease the wattage. I find ordinary incan and LED more foolproof to mess around with - no ballast, pretty straightforward function, harder to break, that sort of thing.

That said, though, I think the biggest barrier to HID (for me) is cost. I can't justify spending several hundred dollars on a beautiful ready-made solution when an ugly homebrew build would be much cheaper and just as effective for my purposes, which are basically nothing, since my only use for this kind of output is plain ol' fun. If it NEEDED to work in a life-or-death situation, I would likely go for one, but the most dangerous thing I do is driving on the freeway, and I don't need a flashlight for that.

My bottom line on HIDs: cool stuff, but no thanks.


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## QuinnK (Jun 22, 2007)

I would have to say... for all it's warts and bumps in places, this thread has overall presented a fascinating volume of interesting information so far... some very knowledgeable folks involved. May it continue as long as that remains so, hopefully kept between the ditches somehow. 
:touche:
All the best... Quinn


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## Icebreak (Jun 22, 2007)

wrathothebunny -

I've added another question. There is a point that seems to be escaping that I'm attempting to re-address.

I also have some answers.

1) Environment: Fair to poor office lighting.

Would light from a blue LED peaking near 470 nm help or hinder in reading small print?

Answer:

It depends on the individual. Some people report that it blurs the print and hurts their eyes, some report there is not much difference, still others report a significant increase in their ability to read small print. One legally blind individual reported being able to retain their job which required reading small print simply by employing the use of a blue LED torch. He could not perform this function without the aid of blue Inova even with powerful glasses.

2) Environment: Low ambient lighting during a stage presentation such as a play.

Would light from red LEDs peaking near 625 nm spotting the target character help or hinder in defining the image of the target character?

Answer:

It depends on the individual. Some members of the audience will experience little effect in definition; others will notice a slight blurring; still others will notice some increase in definition. What most audience members will notice is a different definition rendition as well as a different depth rendition in comparison to everything else on the stage. These two differences highlight the target character and set that target character apart almost as much the obvious difference of the red color.

One individual reported that they were so visually impaired that they could barely navigate in low ambient light situations without the use of both a powerful blue light and a powerful red light used simultaneously. They designed and used a head mounted dual LED device to successfully satisfy this need.

3) Environment: Woods/Forest at night, clear sky, away from population and no moon.

Would light from a cyan LED peaking near 505 nm help or hinder vision in the area of defining the target image?

Answer:

It depends on the individual. Some individuals report that they lose so much color rendition that they feel almost bewildered. Others report a preference for cyan in this environment due to its definition of target capability as well as its particular color rendition capability. With effort, individuals can train their eyes/vision processing to take advantage of the aspects some wavelengths afford.

4) Environment: Woods/Forest at night, clear sky, away from population and no moon.

Would light from a royal blue LED peaking near 455 nm help or hinder vision in the area of defining the target image?

Answer:

It depends on the individual. Some individuals report a blurring effect; others nothing; others reported that it was pretty. One individual reported that he could read distant signs he could not possibly read without royal blue light returning the image. Other individuals substantiated this report with their own real world investigations.

5) Environment: Low ambient lighting during a stage presentation such as a play.

Which of these colors of light would be easiest to hide from the audience on non-target backgrounds; blue 470 nm, red 625 nm, cyan 505 nm or royal blue 455 nm?

Answer:

blue 470 nm.

6) Environment: Medical diagnosis.

Which color of light would be best for diagnosing subdermal vascular anomalies; blue 470 nm, red 625 nm, cyan 505 nm or royal blue 455 nm?

Answer:

red 625 nm

Source of answers


7) Environment: World.

Which personal lighting tool is better for rendering diverse target images; LED or incandescent?

Answer:

It depends on the target and possibly more importantly it is dependent on the individual observer. All perspectives are valid.

While night fishing I prefer to use a tiny LED torch to tie lures, a no-spill TIR LED torch to spot the fish the guy twenty feet from me just pulled on shore and a powerful incan torch to see if that's a small branch or large snake floating in the water. Not everyone will prefer my choices. Individuals see images differently and process those images differently. Some folks have no problem identifying an un-moving mostly submerged cotton-mouth water moccasin at 30 feet out using an LED flashlight.

I hope that was of some help.


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## CLHC (Jun 22, 2007)

Simply put for me, I still prefer incandescents followed by LEDs. Why not EDC both as the saying goes around here on CPF. Well, I do--in the form of the SureFire.A2!

Enjoy!


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## 2xTrinity (Jun 22, 2007)

> Nonetheless, mesopic vision is characterized as using both rods and cones to perceive the environment. I find it very difficult to believe that this does not happen at night with use of a flashlight. Again, this seems to be very tricky to pin down precisely, and I suggest testing this hypothesis in vivo outdoors at night with red and blue LEDs.


I actually tested this out with some low-output red, green, and blue LEDs. Indoors all three appeared near the same. Outdoors, the red appeared so dim that I thought something was wrong with it, output appeared to be almost nothing. Blue appeared much brighter, but was minimally useful as it only lit up certain things -- particular kinds of flowers, and the retinas of about 15 rabbits that started sprinting simultaneously. Green was by far the most useful -- just about everything reflected it to some extent, and even with very low amounts of it, I could see quite clearly.




> 1) Environment: Fair to poor office lighting.
> 
> Would light from a blue LED peaking near 470 nm help or hinder in reading small print?
> 
> ...


I also tested different LED to see how well I could read fine print with them, from best to worst:

green, amber, cyan, UV, blue, red-orange, royal blue, red, violet

Essentially, the nearer to the center of the visible range (~550nm) the better. The UV is a weird exception though as it caused the paper I was reading to fluoresce.


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## jtr1962 (Jun 22, 2007)

BB said:


> Right now the only folks that are trying to kill incandescents are our lawmakers... Nobody here wants to outlaw them.


And the proposed laws wouldn't affect the type of bulbs we use here anyway, just incandescent household general lighting. To that I say good riddance. Given that we've had viable replacements in CFLs and linear tubes for well over a decade I've always found it amazing that so many still even use incandescent to light their homes.



> But people are voting with their feet (and their wallets). What will it be like next few years--haven't a clue.


Only an educated guess but I think besides incremental efficiency improvements the main improvements in LEDs over the next few years will be in tint consistency, color rendering, and cost. I expect LEDs to start to be binned like fluorescents, in common color temperatures (3000K, 3500K, 4100K, 5000K, 6500K), and in various CRI grades (perhaps 75, 85, 90). Cost should drop dramatically, efficiency will probably improve to 100 to 150 lm/W. Given all this, I wonder in a few years if we will even see any more threads like this. For now incandescents may have an edge in color rendering of organic scenes, but as some have said this is often outweighed by the practicality of LEDs. They may also have an edge in output/ease of beam collimation, but here again LEDs are making great strides. The truth is in all honesty I don't see that incandescent will have any real advantages at all in a few years time for _any_ application. Even today focused light really remains its last stronghold. Should be interesting to revisit this thread around 2010 or so.


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## BB (Jun 22, 2007)

jtr1962 said:


> And the proposed laws wouldn't affect the type of bulbs we use here anyway, just incandescent household general lighting. To that I say good riddance. Given that we've had viable replacements in CFLs and linear tubes for well over a decade I've always found it amazing that so many still even use incandescent to light their homes.



The only things I trust our legislature for is to write laws that have marvelously weired unintended consequences and make taxes go up.

-Bill


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## jtr1962 (Jun 23, 2007)

To settle the argument over the supposedly low CRI of Cree XR-Es, at least according to their product documentation:

Independent lab test of two Cree XR-Es

Note the CRI figures of 77.9 and 78 for the two samples with CCTs of 6110K and 5979K, respectively. Too bad they didn't test a WH bin, although with a CCT of 5000K or so I imagine it would get into the low 80s at least.

Note that a CRI of 78 is about on par with the lower grade of triphosphor fluorescent tubes, and very close to the 80 to 82 of CFLs. Both are considered acceptable for general interior lighting, an application where CRI is arguably more critical than for something like a flashlight.


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## Daekar (Jun 23, 2007)

Icebreak said:


> I hope that was of some help.



You ever get the feeling that all your effort is unappreciated? I hate when I got through the trouble to present a lot of information and people just proceed as if I hadn't just slammed the door by rendering further discussion moot and pointless.

At any rate, I greatly appreciate the time and effort it went through to compile all that information, and hope I am correct in assuming that your general point is this: Use what helps YOU see the best. :twothumbs


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## QuinnK (Jun 23, 2007)

It's not all that difficult to settle the incan vs LED thing on a personal level. It's easy enough to determine your own needs or choices as to brightness, runtime, battery use, etc. As far as the color balance between the two, it's also easy enough to compare the two in whatever environment you feel is desirable. Then simply use whatever you prefer for whatever purpose you intend to use it for.

The technical info and research is very interesting and worth delving into, but disagreeing with someone on their choice between the two seems rather pointless. As long as a user takes the time to determine their own preferences and is satisfied with their choice, or choices, it's a little difficult to disagree with that on any practical level. I do like to gather information, opinions, and suggestions to allow me a working knowledge of my options... but I then determine what fits my own needs, interests, and preferences. The reality that someone else will likely come up with a different choice for the same situation shouldn't bother anyone at all, even if they have a different take on the 'facts' behind the options. Still all a matter of personal preference at the end of the day. 

Everything is definitely not a matter of opinion, there are provable facts on all sorts of things... but the choices we make because of (or in spite of) those facts and the subjective elements involved, remain our own province.

Take care... Quinn


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## Icebreak (Jun 23, 2007)

Daekar said:


> At any rate, I greatly appreciate the time and effort it went through to compile all that information, and hope I am correct in assuming that your general point is this: Use what helps YOU see the best. :twothumbs



Thanks, Daekar. I did get a couple of PMs expressing interest and appreciation.


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## chasm22 (Jun 23, 2007)

Bogus1 said:


> Very nice post on the facts wrath! I would have to assume (and hope) the "hater" aspect of the thread is tongue in cheek and intended to keep a thread lively. Let's try not to get stodgy here and I can only hope it's obvious there are different tools for different jobs and that this fact was not overlooked by wrath in an effort to have fun. You aren't going to take a car on a bike path, but both will get you somewhere.
> 
> We've had similar threads before but you put this one very well. I've even been able to 'cruise' forests at night evaluating large trees for health with an incan. Even a clustered LED light just as bright as an incan serves virtually no purpose in a natural setting where 'what it is' you are looking at matters.
> 
> ...



I still keep going back to this post and post #1. Bogus1 makes an argument that is impossible to argue with IMO.

Some have argued that wrathothebunny isn't listening to the otherside. Maybe. But I think the otherside is composed of too many white wall hunters who love the way their led's light those walls up. 

To me this boils down to something we used to call "seat of the pants" testing back in the day. Forget the charts, forget the studies. Take a couple of nice incan powered flashlights and a couple of nice led flashlights. Shine them on anything close or far away in an environment where they are the sole provider of light and truthfully tell me/us what produces the most natural rendition of what you are lighting up. 

I'm not a LED hater or a incan lover. But I do know [email protected] and he looks more natural lit up with an incan.

All the above being said I find myself being tugged back to LED's by the power of the Darkside, otherwise called the P4. I remember long ago in a galaxy far away how this addiction got started with a R2. Actually it was a R2H in a McGizmo modded KL head. :tinfoil:. I still have that light saber around here somewhere. R2, where are you?


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## Daekar (Jun 24, 2007)

I was directed toward some spectral distribution graphs by another CPF member, and found something that may be of interest. Sunlight, at least as perceived inside, is not as heavy in the red end of the spectrum as proponents of incandescents would have you believe. Please excuse the large size of these images, they're not mine, credit for their creation belongs to The LED Museum.

First, our standard: Sunlight through a window in California.






Note the ample wavelengths of central colors which then slowly recede as wavelengths move higher and lower. In particular, note the comparative intensity of red and green wavelengths.

Here are several incan lights.
10x Dominator, High





10x Dominator, Low





SF E2D





Gerber Carnivore





Notice how at 675nm, for instance, the sun has an intensity level of about 1300, whereas the good incans (don't tell me SF uses cheap incan bulbs) have a rating of around 2000-2500. This difference is slightly exaggerated, as a ratio of wavelengths is required to illustrate the true difference. For example, in the sunlight: 
Ratio for green/red (525nm/675nm), 3500/1300=2.69
Ratio for yellow/red (575nm/675nm), 2500/1300=1.92

Now look at the incans: 
Ratio for green/red (525nm/675nm), 3600/3000=1.2
Ratio for yellow/red (575nm/675nm), 3900/3000=1.3. 

At close examination, thats a lot more red and yellow light per green wavelength than the sun, (which would explain the yellow/orange/red color of incandescents when shone in the sun) and consistently less blue wavelength as well.

Now for some LEDs.

P2D-CE





P3D-CE





EverLED (Some kind of Luxeon)





Immediately noticeable is the _enormous_ deficiency is the cyan wavelengths in all three of these premium emitters accompanied by a surplus of blue wavelengths. This would certainly have an effect on the appearance of certain objects - to what extent is probably subjective. However, let us return to our comparative analysis of the green/red and yellow/red ratios. The green/red (525nm/675nm) ratios for these emitters are:
P2D-CE: 3600/650=5.538
P3D-CE: 2750/500=5.500
EverLED: 3900/500=7.800

The yellow/red (575nm/675nm) ratios for these emitters are:
P2D-CE: 3350/650=5.153
P3D-CE: 2500/500=5.000
EverLED: 3100/500=6.200

Whereas in the incans we find a surplus of red light, these ratios unsurprisingly reveal a severe deficiency in the LED spectrum in the middle to low wavelength red light. What should be surprising, however, are the relatively high levels of yellow and orange light in comparison to LEDs of the past. They certainly don't possess the diversity of wavelength that incans do, but LEDs are now certainly capable of useful rendering of a much wider range of color than previous models. While the lack of red may make them less useful for search and rescue, military operations, or car headlights, LED emitters seem to be more than adequate for most tasks demanded of them and are well on their way to achieving a more respectable position in more diverse lighting applications.

In the end, we must conclude that if it is neccesary to see something blue, use an LED. If you need to see red, use an incan. If you need to see cyan, well... you're just screwed, neither has very much, although incans seem to be marginally better. The other central wavelengths are well covered by both types of light and really don't constitute the stuff of a debate. In general though, for task lighting, either is fine. If you prefer additional red wavelengths at the sacrifice of runtime, incan is untouchable. If you prefer blue or don't care about red and want more runtime, LEDs are out of this world. Really... they're different. Don't bother comparing them too much...


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## Bogus1 (Jun 24, 2007)

These are great graphs to be sure, but the color we see from the sun is not static and varies by location, time of day, time of year, and by a host of environmental factors. There is sometimes a tint to windows as well.


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## WadeF (Jun 24, 2007)

What I don't get is when I shine my LED light on various objects that are various shades of red, orange, etc, they look red, orange, etc. From reading all this it sounds like if I was in a pitch black room and lit up something red with my LED it wouldn't appear red? Not the case from what I've experienced.


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## 2xTrinity (Jun 24, 2007)

> In the end, we must conclude that if it is neccesary to see something blue, use an LED. If you need to see red, use an incan. If you need to see cyan, well... you're just screwed, neither has very much,


Looking at graphs of the spectrum is deceptive, as it would lead one to believe that the "Smoother" the graph, and the closer the shape of the power vs wavelength curve to sunlight, the better the quality of the light. While this may generally be true, it's not always the case. In practice, I find the lack of cyan it's almost irrelevant -- shades of blue, and blue-green are rendered quite accurately with phosphor LEDs, because for the most part, things that appear cyan or turquoise will generally reflect a combination of green, and blue light that the brain will interpret as cyan anyway. The lack of red output in most phoshpor LEDs is a bigger problem, as the brain really can only detect varying intensity of the three primary colors. This will cause reddish things to slightly more orange, or more commonly very dim. Even with the best phosphor LEDs, things like skin will look somewhat more pale, for example.

If you look at the graph of a premium triphosphor fluorescent, or ceramic HID lamp, those will appear a lot "worse" than the LED in that the appearance of the graph will have tons of "spikes" rather than a smooth, continuous curve. However, in re0ality, both the premium fluorescent and HID (I'm talking the ones with CRI over 90) do a better job of rendering color than typical LEDs. because the "spikes" are fairly equally spread across all ranges of the spectrum. 



> These are great graphs to be sure, but the color we see from the sun is not static and varies by location, time of day, time of year, and by a host of environmental factors. There is sometimes a tint to windows as well.


The biggest difference with ANY comparison to natural light is intensity. If you were to take an LED with a 8000K tint, everyone would say that it looked awful, and completely unnaturally. Yet, if anyone were to take a walk outside on a cloudy day, or on a sunny day in the shade, the overwhelming source of the light would be very cool diffused skylight at close to 8000K. Yet even in that environment shades of reds can still be distinguished since the intensity of light is so great (orders of magnitude greater than any artificial light). 



> To me this boils down to something we used to call "seat of the pants" testing back in the day. Forget the charts, forget the studies. Take a couple of nice incan powered flashlights and a couple of nice led flashlights. Shine them on anything close or far away in an environment where they are the sole provider of light and truthfully tell me/us what produces the most natural rendition of what you are lighting up.


When comparing my best LEDs to my best incans, I find the incans are still superior outdoors, but the very best result is found by running both at the same time.

Consider that outdoors in the daytime, there are always essentially two light sources -- direct sunlight (warmer), and diffused skylight (cooler). Indoors I find I prefer cool white light for area lighting, and warmer white light for spotlighting/accent lighting.

For flashlights I still think a neutral white light source will peform better than a very cool (LED) or very warm (incan), in general, provided that it has high CRI and is not deficient in some portion of the spectrum. My 4200K HID is pretty close to ideal, but is still weak in extreme blue, and extreme red (it has a strong greenish tint).


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## tvman (Jun 24, 2007)

Kudos to Mr. IceBerg (IceBreak) for simplifying the complex hue and chroma aspect of light to those of us heathens (me) who adhere to the wave-particle duality theory. Mr. Planck would be so proud he probably would roll over in his grave and perform the Time Warp or better yet the Benes dance. I love your rhetoric which totally flattens me and is great for dulling the senses - anybody got a cot for a nap? Just try to limit the corpses laying around for those subdermal vascular anomalies tests.

Jeers aside, thank you very much for the lessons on the color spectrum. 

Iceberg,

Could you exhort and elaborate on the existential pleasures of engineering?


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## BB (Jun 24, 2007)

Linear plots of spectrums are virtually useless for representing the light we see...

3/4 of the vertical graph's (4,000-1,000 "counts") represents only a 4:1 ratio or about 6db range. Your eyes can hardly discern a change between 4,000 and 2,000--but that is fully 1/2 of the data set represented.

Remember the range of our eyes for any one scene? 10,000:1 or 40db. That "scrunched area" of the bottom 1/4 of the graph contains the other 44db or 2,500 more "information" that your eyes use for processing that it would appear if you only looked at the 1,000-4,000 range of the graph and "ignored" the "noise" of 1,000-0.4 counts.

-Bill


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## FloggedSynapse (Jun 24, 2007)

wrathothebunny said:


> Ok, I just want to clear this up once and for all - quality of light matters! Have you guys ever heard of the 4 C's of diamonds: cut, color, clarity, and carat weight? The first 3 address quality, and the last addresses quantity. Sometimes, one gets the impression that the only thing that matters to the LED fanatics on these forums is quantity - meaning lumens and runtime. Lumens and runtime have NOTHING to do
> 
> *Why the Beam Spectrum matters:*
> 
> Primarily, beam spectrum matters because we live in a world of color, and different colors absorb, refract, and reflect back different wavelengths of light differently. So, different wavelengths of light emitted by your flashlight will react differently with your environment, thus affecting how you perceive the colors of your environment - often in ways that affect your visual acuity and impacts perceptions of contrast and depth - in addition to just plain color accuracy.



(Ug, another incan vs. LED thread. Such a guy thing: A vs B - which is larger, faster, better, whatever. I've got some time to kill this evening, however this will be my only post to this thread)

Look, babe, no one is going to be dispute that for discriminating visual tasks incans usually will give better color rendition and contrast detection. However, with the latest crop of LEDs out there, this point is moot for most people. One thing about the spectrum of the latest LEDs - I think the notch in the green part of the spectrum (around 500 nm) is more important than the lack of deep reds. Sunlight has a peak in the green part of the spectrum (and it's no surprise the peak senstivity of the eye in good light corresponds to this) so this a big deficiency with the LED spectral output, IMO.

The nature of vision is a very complex topic, and what you need to realize large parts of it _are_ subjective, and always will be. No two pairs of peepers are the same, and those sensitivity curves are just averages made from many different observers.

My take is the reason you're using a flashlight is to engage your photopic visual system. Almost all discerning vision in good light uses a tiny part of the retina, no more than 2 mm across - the macula (fovea). Here nearly all the color sensitive cone cells are found. Over 95% of all cone cells are sensitive to red/green light, which is why this part of the spectrum is important for discerning vision.
(See this thread:
https://www.candlepowerforums.com/threads/142836
)


In low light conditions things are more complex. In the darkest conditions (moonless night) only rod cells are active, with the cone cells dormant (monochromatic night vision, which most people never really experience with all the light pollution these days). Under these conditions (or using mesoptic vision) LEDs may have an edge cuz the dark adapted eyes sensitivity shifts towards the blue part of the spectrum.

Anyway, for ME, LEDs are where it's @. I'm not using them for surgery, I'm using them in very dark conditions when I need light. I've got a CR2 ion that I now take on my nocturnal hikes. This amazing light is about the size of a chapstick, and on the regulated low setting l get over 35 hours of light. On top of that it's robust (no broken burned out bulbs) and has an excellent smooth flood output, perfect for navigating dense single track and turkey trails on moonless nights. It's CRI is whiter than nearly all incans out there. On the darkest sections of trail the 5-7 lumens of light provided are more than enough for me to navigate. For most people the practical benefits of the current batch of white LEDs make them a better choice than incans. YMMV of course.


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## KingGlamis (Jun 24, 2007)

You guys can post data and graphs and info all you want. I go by real world results. I can see the difference between incan and LED, we all can. Two different things. I buy and use what works for me. No need to argue the supposed stats, just buy what works for you.

I will agree that much of the tech info posted here is useful, but with four sides to every opinion, I have given up listening to the "experts" and decided to review each and every light on my own terms to decide if I will buy it. That is often hard, but I will try.


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## wrathothebunny (Jun 25, 2007)

Ok, I'm back from my weekend trip  and I wanted to weigh in real quick (I'll post more substantive info later when I get a chance).

I know the topic has moved away from this point since I've been gone, but I wanted to briefly address the whole scotopic, mesopic, photopic bit one more time, for those who are interested, as it applies to night levels of illumination.

Now, previously, we have been referring to mesopic visual levels in candles per square meter - with roughly 3.4 candles per square meter representing the upper end of the mesopic boundary. However, more precise research into mesopic functioning does not really quantify the luminance values in cd/m^2 - rather, they take it one step further, and quantify it in something called trolands - which is candles per square meter per mm^2 pupil size. So, the more the pupil constricts, the higher the outside luminance can be while still falling within mesopic vision. So, the 3.4 cd/m^2 ambient luminance limit for mesopic vision is hardly firm if the pupil has cause to be more constricted.

Now, what could cause the pupil to constrict? Well, varying illumination levels for one. If you look at the hotspot of your flashlight beam then to the spill, your pupils will be more constricted than if you were just looking at the spill. But here is another interesting factor, it has been substantiated through research (can provide reference upon request) that the pupil is more reactive to blue light than warmer light, supporting the theory that there is a rod input to pupil reactivity. So, that blue spike you see in your LED spectral power distribution curve will serve to further constrict your pupil per given quantity of light more than an equivalently bright light source with lesser blue spectral content would (like an incan). *However, blue light will also saturate the rods more quickly, so this might make this second factor a wash when it comes to mesopic vs. photopic visual functioning. The first factor, however, is still very important and should relate to any night time conditions with only partial illumination, such as using a flashlight or headlights on your car for that matter*

So, for these reasons, a more constricted pupil will result in less trolands reaching the rods and cones, thus increasing the luminance levels in which mesopic visual processing can occur. In any case, this is all very silly, as the high wattage halogens that beam out from the front of your car during night driving are typically characterized by visual researchers as providing for mesopic visual conditions, even with the addition of street lighting. If your headlights don't push you completely out of the mesopic range, then it may not be a foregone conclusion that your flashlight does so either.

Now, why is mesopic functioning important? Because a little goes a long way in night adapted eyes when it comes to blue light, as the rods that are active in mesopic vision are very sensitive to blue light, whereas they hardly register red light at all. So a little blue goes a long way, but it takes a whole lot more red to provide enough luminance for the less sensitive cones to register it. So, the criticisms that incans have too much red but not enough blue is mitigated by this phenomenon, and, in fact, it can actually be seen as a positive in providing for a rendering of detail in the environment with greater fidelity. 

Now, the deficiency in red in the LED spectrum leads to the possibility that the levels of red light reaching the retina, after having passed through a more constricted pupil thanks to that blue spike of light, fail to reach such levels as necessary to activate the cones and provide much red color information for rendering the environment. In fact, this is what my eyes see when I go outdoors at night with my LED Fenix P3D. It literally looks like someone did a Photoshop function, removing almost all the red from the image. Red dirt actually looks almost grey, which would be consistent with the more sensitive rods processing the light reflecting from the dirt, but with the small amount of red spectral light produced from the LED failing to provide enough stimulation to the cones to begin firing and thus registering the ground as red.

There is also the further negative side-effect of LED white light with the high blue spectrum spike - blue light most excites your rods and your rods are most responsible for your night vision, so the more you excite them, the more you lose your night vision. So, higher exposure to the blue light produced by LEDs means a greater length of time to return to dark adaptation, whereas the lower content of blue light produced by incandescents results in a faster dark adaptation recovery, as the rods are being excited less, and the cones more. This is not to say that high content in blue spectral light is always bad, however. At low levels of light (mesopic and scotopic), blue light provides for greater illumination at equivalent lux levels, so in street lighting, it is often important to have high blue spectral light, because lighting efficiency is such a huge issue and you get more "bang for your buck," so to speak, with bluer light. The same does hold true with flashlights, a white LED with high blue spectral content will out illuminate an incandescent with low blue spectral content at equivalent lux. The problem is, several of the flashlights popular in these forums provide more than enough illumination for many night environments, and too much illumination destroys night vision. So, again, LEDs win with efficiency as it relates to quantity, no doubt about it. It is when you have sufficient quantity with both incandescent and LED lighting options, per a given task, that the qualitative rendering properties of light come in to play in choosing between the two

To sum up, those criticisms that allege that the low blue and high red spectral content for incandescents is just as bad as the high blue and low red spectral content for LEDs should find a rebuttal in my argument in this post. Higher quantities of blue light can constrict pupil diameter and stimulate (thereby reducing the sensitivity of) rods, resulting in poorer night vision. Higher quantities of red do not have nearly as severe effects on night vision, allowing the pupil to remain more dilated and the rods more sensitive as well. Additionally, the lack of red in the white LED spectrum desaturates organic colors rich in red, with potential effects relating to contrast and visual acuity of detail in the environment.

Like I said, however, I'll get to the very excellent points a lot of you have been making, but till then, I just thought I'd post this info.


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## Learjet (Jun 25, 2007)

Dim incans seem to be better when doing astronomy as they preserve dark adaption better than leds. I remember taking my 1aa incan to the astronomy club and had no trouble walking back to the car with the pale yellow light. A single led on the other hand seemed to ruin night vision.


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## wrathothebunny (Jun 25, 2007)

Daekar,

Thanks for providing your insightful graphs, but the SPDs for your SureFire Incandescents don't look right. The red should be the most substantial component, with the rest falling on a slightly curved diagonal slope downward towards blue and violet (having the least). So it should look somewhat like this (picture posted for a CCT 3400K source - the better SureFire's can reach 3300K). Due to this discrepancy, I have to wonder about the accuracy of the readings you pulled from the LED museum (also, measurements should really be taken over a range of conditions as sunlight varies greatly throughout the day and through different weather). Now, to you this curve may actually look worse, but when night-time mesopic processing conditions are taken into account, this helps to preserve night vision while simultaneously ensuring greater color rendition of your environment, rather than the desaturation that takes place with most white LEDs.


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## mchlwise (Jun 25, 2007)

wrathothebunny said:


> ... I have to wonder about the accuracy of the readings you pulled from the LED museum ...



Now you're going to question LED museum's data!? :green:

Just because someone has data that doesn't agree with your conclusions doesn't mean their data is wrong.


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## wrathothebunny (Jun 25, 2007)

Mchlwise,

Yes, I am going to question the peer reviewed, infallible, academically recognized LED museum when confronted with scientific knowledge that has been known for, at a minimum, decades. *Incandescent, tungsten-filament based light sources emit primarily infrared light. Have you ever wondered why it is called "infrared?" Well, infra is Latin for "beneath" and red is, well, red. So the longer wavelengths of infrared begin at the very end boundary of visual, deep red. It is common scientific knowledge that tungsten-filament bulbs produce a peak in the infrared region, with a downward slope extending into the visual region. This does not reconcile with the LED muesum's data. And this is not one source that disagrees, virtually any scientific publication in the field of vision and related physics will also substantiate this.*


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## mchlwise (Jun 25, 2007)

wrathothebunny said:


> Mchlwise,
> 
> Yes, I am going to question the peer reviewed, infallible, academically recognized LED museum when confronted with scientific knowledge that has been known for, at a minimum, decades.



I'm not sure, but I think you're being sarcastic.


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## wrathothebunny (Jun 25, 2007)

Hmmm...could be possible.


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## Outdoors Fanatic (Jun 25, 2007)

wrathothebunny said:


> Mchlwise,
> 
> Yes, I am going to question the peer reviewed, infallible, academically recognized LED museum when confronted with scientific knowledge that has been known for, at a minimum, decades. *Incandescent, tungsten-filament based light sources emit primarily infrared light. Have you ever wondered why it is called "infrared?" Well, infra is Latin for "beneath" and red is, well, red. So the longer wavelengths of infrared begin at the very end boundary of visual, deep red. It is common scientific knowledge that tungsten-filament bulbs produce a peak in the infrared region, with a downward slope extending into the visual region. This does not reconcile with the LED muesum's data. And this is not one source that disagrees, virtually any scientific publication in the field of vision and related physics will also substantiate this.*


If I were LED fundamentalist, I would kindly shut my trap after reading these arguments...


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## mchlwise (Jun 25, 2007)

wrathothebunny said:


> *Incandescent, tungsten-filament based light sources emit primarily infrared light. Have you ever wondered why it is called "infrared?" Well, infra is Latin for "beneath" and red is, well, red. So the longer wavelengths of infrared begin at the very end boundary of visual, deep red. It is common scientific knowledge that tungsten-filament bulbs produce a peak in the infrared region, with a downward slope extending into the visual region. This does not reconcile with the LED muesum's data. And this is not one source that disagrees, virtually any scientific publication in the field of vision and related physics will also substantiate this.*



Seems to me you could have posted this (edited in later) information without the initial sarcasm. 

LED Museum states that the observations are through a window. 

It seems to me that it brings up a question as to how (if your information is accurate) the window glass would affect the light coming through it; i.e. filtering of infrared. 

If the window glass would have an effect, then wouldn't also the glass lens/window of the incandescent flashlight? 

Wouldn't the light from said incandescent flashlight then look very similar to LED Museum's readings?


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## mchlwise (Jun 25, 2007)

Outdoors Fanatic said:


> If I were LED fundamentalist, I would kindly shut my trap after reading these arguments...





I'm not sure how to define "LED fundamentalist" so I don't know if I am one or not, but I just posted a counter-argument which I think is more than trivial and would like to see discussed.


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## mchlwise (Jun 25, 2007)

Now that I think about it...

Since we're talking about light going through glass, what kind of "filtering" happens to LED light? 

Does the glass filter on the ultra-violet side of the spectrum also? What effect does this have on the "blue spike" of the LED? 

Were the LED spectrums read through glass, or on a bare emitter?


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## dano (Jun 25, 2007)

This thread has turned into a public pissing match between two members, who have been warned previously.

This thread is done.

-dan


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