# 4Sevens Preon 2 Warm White Comparison Review



## UnknownVT (Jun 1, 2010)

From the limited run of 4Sevens Warm White emitters - 
this is the Preon 2-W (2xAAA Cree XP-G Q5 7A or 7B bin).

This is from the same run as 
4Sevens Quark AA-Warm Comparison Review
see that review for more details of the chromaticity binning etc of this warm white emitter.

Size:





the Preon 2 is a 2xAAA "penlight"

Head:




one can recognize the warm white emitters by the more orange-yellow coloring in the reflections.

These warm white emitters are centered around color temperature of about 3100degK - which makes them imitate/mimic a good xenon lithium light like the SureFire 6P, Streamlight Scorpion etc - it's just that this diminutive AAA penlight is more than twice as bright on max, and has three handy levels of light. 

vs. Preon 2-R5 Cool White (see 4Sevens Preon 1 (1xAAA) ) both max and NiMH







well the R5 cool white is brighter but it is shown to be quite blue in comparison - while obviously the Warm looks amber.

vs. 4Sevens Quark AA-Warm both Max and NiMH







of course the Preon 2-W is brighter - stands to reason as it's driven by 3V of 2xAAA vs. the 1.5V of the Quark AA - but after I took this series of beamshots I realized I should have compared the Quark on 2xAA - so here it is:

vs. Quark AA2-Warm White - both Max and NiMH







now the Quark Warm White head on 2x AA is brighter.......

vs Neutral White 4Sevens Quark AA both Max and NiMH







the Preon 2-Warm is obviously brighter - again I should have compared the Quark NW on 2xAA as well - but this is enough to show the tint difference and if one wants more comparisons see the 4Sevens Quark AA-Warm Comparison Review.

*EDIT to ADD* - seems silly to talk about what I should have done, and not do it....

So here is the comparison -
vs. Quark AA2 Neutral White (Q3-5A3) both max and NiMH







now that Quark Neutral White head is brighter on 2x AA NiMH

Preon 2W medium level vs. Streamlight Scorpion Xenon 2x CR123







the medium level of the Preon 2-W was better for comparing the tints even if it is rated at only 22 lumens whereas most know the Scorpion is a real 60 lumens - the Preon 2 has a much more concentrated/narrower side-spill making that part brighter - whereas the Scorpion has a very wide (wonderful) side-spill and brighter hotspot in comparison.

The tints look similar - although in real life I see more pale straw yellow as the Scorpion's beam with a tiny hint of green - again please see Post #*8* (link) in 4Sevens Quark AA-Warm Comparison Review for a discussion of the limitations of the beamshots in their ability to capture this difference that I can see.

Preon 2-W on Low vs. 2AA MiniMag krypton 2x AA Alkaline.







krypton lights are a bit warmer than xenon bulbs - and the beamshot does show the MiniMag being a bit more red - and this time the warm white emitter seems to have a tiny hint of green in comparison - this set of shots looks about the same as I see it.

The Preon 2-Warm is a handy little light and if the early feedback is any indication - seems destined for use by savvy medial personnel in place of their traditional medical incandescent penlights.


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## paulr (Jun 1, 2010)

I have the so called neutral white Mini 123 and its color temperature is much less blue than the typical cool white, but I think its CRI is not that great. They are different things. The WW may have the same issue.


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## UnknownVT (Jun 1, 2010)

paulr said:


> I have the so called neutral white Mini 123 and its color temperature is much less blue than the typical cool white, but I think its CRI is not that great. They are different things. The WW may have the same issue.



I have read posts where people seem to imply that white LEDs are achieving respectable CRIs - BUT my own minimal searches on the web seem to find that the best of LEDs in flashlights appears to be the LumiLED's Rebel series at CRI=70 - this is significantly below even an average GE household CFL (compact fluorescent) at CRI=82.

I do not know what the Crees CRIs are - but I would guess it cannot be much above the Rebels - otherwise we'd all be hearing about it.....

Having said that among the flashlight available tints I like the Neutral whites the most - mainly because it seems a good compromise between the rather harsh Cool Whites and the too amber/yellow of the Warm Whites - I think avoiding the too green-blue of most of the Cool Whites does it for me.

However looking at the Cree binning on the chromaticity chart - they obviously have bins that are closer to "sunlight" 5000K - most cool white LEDs are about 6500-7000K - plus driven to the max which tends to make them even cooler and bluer, and due to the phosphor tends toward green-blue...... Hopefully some forward looking maker will look more seriously at emitters rated closer to sunlight at about 5000K instead of always going for these harsh too cool Cool Whites - perhaps we can then have more pleasant "Cool White" LED flashlights - I think there may be something in our make up that most find "sunlight" pleasant. The Cree bin closest to "sunlight" 5000K would probably be bin *3A*.

However getting back to these Warm White emitters bin Q5 7A or 7B are at about 3100K - and does imitate/mimic a good xenon lithium flashlight - perhaps just on the shade of the warmer side - but they are cooler than the average krypton incandescent - so the bin was very well chosen.

In 4Sevens Quark AA-Warm Comparison Review - there have been a couple of initial posts from medical users who seem to find the Warm White does about as well as their existing incandescent (remember incandescent are CRI=100 "perfect" by definition - since they are their own reference!) please see Post #*60* and #*71* (linked) but we will have to wait for more conclusive input to see if these warm whites can replace incandescent for more critical medical usage.

However as an incandescent substitute for the average flashaholic - I think that most who have these think that they do as well as incandescent - but with all the advantages of LED - like being much brighter, and having multiple levels, and obviously much longer runtimes using much less energy.

BTW - there has been a proposed change in the way CRI is measured due mainly to the poor rating of white LEDs - please see CRI of White LEDs.


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## HKJ (Jun 1, 2010)

UnknownVT said:


> I have read posts where people seem to imply that white LEDs are achieving respectable CRIs - BUT my own minimal searches on the web seem to find that the best of LEDs in flashlights appears to be the LumiLED's Rebel series at CRI=70 - this is significantly below even an average GE household CFL (compact fluorescent) at CRI=82.
> 
> I do not know what the Crees CRIs are - but I would guess it cannot be much above the Rebels - otherwise we'd all be hearing about it.....



You are correct about Cree, they are at CRI 75, except the real warm ones, they are at CRI 80.

It is in the data sheet.


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## UnknownVT (Jun 1, 2010)

HKJ said:


> You are correct about Cree, they are at CRI 75, except the real warm ones, they are at CRI 80.
> It is in the data sheet.



Thank you so much for the pointer and link.

DoH! you know I have that pdf - and didn't see it! must have been blinded from looking at these flashlights front-end On!

Here's the relevant crop:





CRI is a funny thing it is color temperature dependent - so cooler and outdoor whites have real daylight as a benchmark, and the warm (and perhaps the neutral) white have a regular incandescent as the reference "perfect blackbody" so may be "easier" to imitate/mimic?

Anyway it's good to see/know that these warm whites actually have a reasonably respectable CRI - FWIW.


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## paulr (Jun 1, 2010)

I have a Nichia 083 High CRI light and a Cree NW light, and it seems to me that the Nichia has much nicer color rendition but is less efficient. In the other thread (if I'm reading it correctly) Nichia claims CRI of 90+ for some of its leds, though I'm not sure if that applies to the 083.


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## UnknownVT (Jun 2, 2010)

paulr said:


> I have a Nichia 083 High CRI light and a Cree NW light, and it seems to me that the Nichia has much nicer color rendition but is less efficient. In the other thread (if I'm reading it correctly) Nichia claims CRI of 90+ for some of its leds, though I'm not sure if that applies to the 083.



Thanks for the hint.

I think it is often a trade-off between output lumens efficiency and better CRI - as in fluorescent lighting 
(eg: I have a GE 13watt 5000K CFL CRI=82, 855 initial lumens, and a GE 20watt F20/T12 5000K tube CRI=90, but only 875 initial lumens for 20watts - the 8 CRI points meant the use of more sophisticated but much less efficient phosphor(s) dropping in comparison to about 67% efficiency, see: GE sunshine 5000K CFL )

The Nichia -183 series appears to be the high CRI - claims of up to CRI=92:

NS6W183-H3 (pdf datasheet) in white (11000-4600K)

NS6L183-H1 (pdf datasheet) in warm white (4600-2500K)

The Neutral Whites used by 4Sevens were Cree XP-E Q3-5A3 - centering around 4100K

their next run would be the Cree XP-G R4-4C0 or 4D0 (which centers around 4350K - a bit cooler)
ref: Poll: XP-G R4, Neutral-White, Limited Run - Pre-order!

The Warm White emitters used in this Preon 2 is the Cree XP-G Q5-7A3 or 7B4 centering around 3100K - much closer to incandescent - esp. xenon-lithium lights


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## djans1397 (Jun 15, 2010)

OK guys, I haqve a simple question with hopefully a simple answer. I need a nice pocket light that I can use at the hospital where I work. I obviously want an LED and recently bought a Preon 2xAAA, but now I found that they have a warm version. 

I've been using some of my other "cool white" LEDS, but want something that give better CR as to better assess rashes, throats and skin in general. What's the general consensus on a light that will do the job for me in an indoor setting? The Preon WW version looks a little too yellow for me, but may be better than the standard version.

Thanks,
Dan


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## UnknownVT (Jun 15, 2010)

djans1397 said:


> I need a nice pocket light that I can use at the hospital where I work.
> I've been using some of my other "cool white" LEDS, but want something that give better CR as to better assess rashes, throats and skin in general. What's the general consensus on a light that will do the job for me in an indoor setting? The Preon WW version looks a little too yellow for me, but may be better than the standard version.



It depends what you've been happy with so far.

Most medical usage seems to have been with regular incandescent lights - because that is what has been available - but despite the fact that they are yellow/amber - the CRI=100 by definition since a tungsten bulb is its own reference blackbody. The reason why incandescent work well with flesh is its abundance in red and yellow.

The Warm White LEDs used in the Preon (and others) in this limited run is XP-G Q5-7A or 7B which is very well chosen with a color temperature centering around 3100K and closest to the Planckian/blackbody locus.

So the WW are close to mimicking/imitating a good xenon bulb lithium light in tint such as the SureFire 6P/G2, 9P and the Streamlight Scorpion, and just a bit cooler than the Krypton bulb MagLites.

Please click on:
4Sevens Quark AA-Warm Comparison Review
where my comparisons were much more in-depth due to the high initial interest of the Warm White emitter used in this same limited run.

Specifically look at Posts #*60* and #*71* (linked)

So if incandescent lights have been good for your purposes then the WW LED in this limited run of the Preon 2 would seem suitable. There may be a lack in the deep red part of the spectrum - I do not know if this is critical or not since I do not use these lights for medical examination.


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## djans1397 (Jun 15, 2010)

Thanks UnkownVT. This is what I was looking for!

Dan


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## UnknownVT (Jun 15, 2010)

djans1397 said:


> This is what I was looking for!



Dan,

Glad to be of some help - although you have to understand my knowledge in the medical area is strictly secondhand and I defer to people who actually use flashlight in their medical professions.

I do hope you'll come back and please let us know your findings - 
the initial feedback seems pretty positive - 
but that could be just a honeymoon period.

But any and all feedback (including shortcomings) from medical type usage would all be very useful.


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## Xak (Jun 17, 2010)

djans1397 said:


> OK guys, I haqve a simple question with hopefully a simple answer. I need a nice pocket light that I can use at the hospital where I work. I obviously want an LED and recently bought a Preon 2xAAA, but now I found that they have a warm version.
> 
> I've been using some of my other "cool white" LEDS, but want something that give better CR as to better assess rashes, throats and skin in general. What's the general consensus on a light that will do the job for me in an indoor setting? The Preon WW version looks a little too yellow for me, but may be better than the standard version.
> 
> ...



I would go with a neutral tint. The Warm is too warm, but perfect for pupils. Some say it's too yellow, mine is too pink. I have an older neutral light from Quark that is just right. If any of the newer XP-G neutrals (due to ship later this month) are similar I would go with one of those.

Like you said, the Warm White XP-G is a LITTLE too yellow. I don't mind that, but in my case I detect a hint of pink. I have a Titanium Innovations IlluminaTi 1xAAA with a standard XP-G that seems a bit blue-green. My older Quark with the neutral tint has the best tint by far. I can't wait to see someone compare the old neutral tint to the new XP-G neutrals coming out. If they are similar that is what you want.

...oh, I'm a paramedic, BTW, and NEED decent lighting at times. These are my findings so far.


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## UnknownVT (Jun 17, 2010)

Xak said:


> I would go with a neutral tint. The Warm is too warm, but perfect for pupils. Some say it's too yellow, mine is too pink. I have an older neutral light from Quark that is just right. If any of the newer XP-G neutrals (due to ship later this month) are similar I would go with one of those.
> 
> Like you said, the Warm White XP-G is a LITTLE too yellow. I don't mind that, but in my case I detect a hint of pink. I have a Titanium Innovations IlluminaTi 1xAAA with a standard XP-G that seems a bit blue-green. My older Quark with the neutral tint has the best tint by far. I can't wait to see someone compare the old neutral tint to the new XP-G neutrals coming out. If they are similar that is what you want.
> 
> ...oh, I'm a paramedic, BTW, and NEED decent lighting at times. These are my findings so far.



Thank you very much for that input.

Very interesting - this is the first time I've seen Neutral White as a preference over Warm White for medical usage. 

Post #*60* in 4Sevens Quark AA-Warm Comparison Review does show a preference of WW over NW - but that is for pupils.

The new limited run of Neutral White will be XP-G R4-4C0 or 4D0 (about 4300K) which is cooler than the previous XP-E Q3-5A3 (about 4100K) whether that makes that much difference I guess only real practical critical usage can tell - as I am not too sure if comparison beamshots will/can reveal that much.

By the sounds of it your WW may be a bin 7A which is on the pink side of the Planckian/blackbody locus - I wonder if a 7B which is on the green side of the locus would have made any difference? 
My guess is that probably not, otherwise the bin selection would be ultra critical - 
whereas the evidence so far is that most incandescents work well for medical usage - and they could range from vacuum to xenon bulbs, so a color temperature range of 2700-3200K - which is quite a wide range of tints, a variance between a bin 7A and 7B would be trivial in comparison - 
so it's probably a peak (or trough) in the spectrum of the WW that does not suit your eyes.

But really good input thank you.


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## djans1397 (Jun 17, 2010)

Great info everyone! Sounds like I may have to just see for myself what suits me as there is likely personal preference involved here. 

Thanks again,lovecpf

Dan


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## Xak (Jun 19, 2010)

UnknownVT said:


> The new limited run of Neutral White will be XP-G R4-4C0 or 4D0 (about 4300K) which is cooler than the previous XP-E Q3-5A3 (about 4100K) whether that makes that much difference I guess only real practical critical usage can tell - as I am not too sure if comparison beamshots will/can reveal that much.



OK, after further review (looking down my own throat in the mirror with both lights) the Warm White wins, for sure. Neutral (XP-E Q3-5A3) is adequate in this area and just fine for overall skin tones if the only source of light. 

If the new neutrals (XP-G) are cooler I have no interest unless the tints in beam shots comparing my old XP-E Q3-5A3 and the new XP-G neutral are not cooler to the human eye, or if it is in a Tac light, like a Maelstrom.

If the new XP-G neutrals were a little warmer than the XP-E Q3-5A3, but not nearly as warm as the Warm White XP-G I would be all over it.


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## djans1397 (Jun 19, 2010)

Xak,

THANKS MUCH for the perrsonal review on this for me!:thumbsup:
This helps immensely as I really want to get the tint that works the best for evaluating ENT and Skin. I'm a Physician Assistant of 17yrs and obviously rely on our lights at work to do the current job. They are your typical Welch Allen wall units, but the newer warm and neutral tints have me all excited for a great source of lighting needs. Thanks for your independant review of these for me. This saves me the trouble from having to buy both tints as I only need one unit.

Thanks:twothumbs
Dan


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## UnknownVT (Jun 19, 2010)

Xak said:


> OK, after further review (looking down my own throat in the mirror with both lights) the Warm White wins, for sure. Neutral (XP-E Q3-5A3) is adequate in this area and just fine for overall skin tones if the only source of light.



Thank you for that input - 
from 3 people who use flashlights medically - it seems that overall the Warm Whites are the way to go over Neutral Whites.



Xak said:


> If the new neutrals (XP-G) are cooler I have no interest unless the tints in beam shots comparing my old XP-E Q3-5A3 and the new XP-G neutral are not cooler to the human eye, or if it is in a Tac light, like a Maelstrom.
> 
> If the new XP-G neutrals were a little warmer than the XP-E Q3-5A3, but not nearly as warm as the Warm White XP-G I would be all over it.



I do not quite understand this.

What is unclear about the new NW XP-G 4C0 or 4D0 are at color temperature 4300K - which is bluer/cooler than the existing previous run XP-E 5A3 at 4100K - that is some 200degK difference which is at least measurable - how can the cooler LED appear to be "warmer"? 

Perhaps what you are looking for is an XP-G centering around about 3500-3700K (maybe a 6B1 or 6B4 bins - since you prefer less pink) which would definitely be warmer than the NW 5A3, and cooler than the WW 7A or 7B

Warm tinted Cree XP-G Q5 - 7A3 or 7B4 bin tint,
compared to the previous run of Neutral white 5A3.
Binning sheet for the Cree XP series -




Warm whites are in the color temperature of about 3100K (green outline) the Neutral white used previously (XP-E) were about 4100K, bin: Q3-5A - (blue-gray circle)


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## Xak (Jun 22, 2010)

UnknownVT said:


> Thank you for that input -
> from 3 people who use flashlights medically - it seems that overall the Warm Whites are the way to go over Neutral Whites.
> 
> 
> ...



I don't know. This guy said the NW XP-G R4 would be cooler than the older NW LEDs used by 4Sevens:

"The new limited run of Neutral White will be XP-G R4-4C0 or 4D0 (about 4300K) which is cooler than the previous XP-E Q3-5A3 (about 4100K) whether that makes that much difference I guess only real practical critical usage can tell - as I am not too sure if comparison beamshots will/can reveal that much."

Perhaps I was wrong. If the new NW XP-G is a tad warmer, I can't wait to get one! In any case the WW XP-G is the clear winner for ENT.


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## UnknownVT (Jun 22, 2010)

Xak said:


> I don't know. This guy said the NW XP-G R4 would be cooler than the older NW LEDs used by 4Sevens:
> 
> "The new limited run of Neutral White will be XP-G R4-4C0 or 4D0 (about 4300K) which is cooler than the previous XP-E Q3-5A3 (about 4100K) whether that makes that much difference I guess only real practical critical usage can tell - as I am not too sure if comparison beamshots will/can reveal that much."
> 
> Perhaps I was wrong. If the new NW XP-G is a tad warmer, I can't wait to get one! In any case the WW XP-G is the clear winner for ENT.



I was that "guy".

You know I still don't understand you - 
and if you're trying to be sarcastic 
- it isn't working.

I say the *same* thing again 
for the third time -
The up coming Neutral White limited run will be bin 4C0 or 4D0 - these center around 4300K that is a _*cooler *_color temperature than the previous Neutral White which were 5A (centering around 4100K).

In other words, the new NW cannot possibly be warmer than the previous NW run.

Hope you got it this time.


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## Xak (Jun 23, 2010)

I think I'm just misinterpreting what your saying. Not trying to be sarcastic. You win, they're cooler. Whatever.


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## UnknownVT (Jun 23, 2010)

Xak said:


> I think I'm just misinterpreting what your saying. Not trying to be sarcastic. You win, they're cooler. Whatever.



OK....

"winning" has nothing to do with it 
(and that seems like a pretty obnoxious thing to say 
considering the only reason I am trying my best to clarify things for the fourth time - is for you).

what may I ask is there to misinterpret about the new 4Sevens bin 4C0/4D0 neutral white being a Cooler bin than the previous 5A NW?

I do understand you wanting a warmer NW than the existing 5A - 
but the new run using 4C0/4D0 bin are not going to be 
the bin is slightly slightly cooler - 
no matter how many times you may wish they are warmer - 
they won't be because of the selected bin is cooler.







I've marked/circled the respective bins: 
the 7A/7B in red is the Warm White bin, 
5A in green is the existing NW bin
and the gray-blue 4C0/4D0 bins are the upcoming 4Sevens NW - 
the higher the color temperature the cooler the tint - 
now granted the the 4C0/4D0 bins are adjacent to the existing 5A bin - 
but they are on the cooler side - 
so they are going to be cooler than the existing 5A - 
I don't think I can be any clearer, or more explicit about this.


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