Changing LED Tint With Filters

[GaAslamp]

Re: I'm an LED tint snob!

I now cringe everytime I see someone launch into tint pontification mode in a thread. I am old enough to have spent a good bit of time taking photographs on film. Sometimes those photos have unavoidably been taken indoors with only an incandescent light source. The results, of course, are a horrible orange cast to everything with very poor colour rendition of cooler colours.

High CRI with spectral imbalance is worse than lower CRI with better spectral balance.

The colors under solid-filament-based incandescent lighting may be inaccurate due to the spectral imbalance (unfiltered), but it's not any worse at rendering cool colors than cool white LEDs are at rendering warm colors. Also, distinguishing between colors is manageable under both types of lighting.

A lot of people deride cool white LEDs declaring them to be unfit for anything because of their complete inability to render warm colours.

Some folks believe that the emission spectra of white LEDs consist of only a few huge, narrow spikes, but it's actually continuous (with some spikes and "valleys" to be sure), so I agree that it's possible to distinguish between most colors, including warm ones (although the accuracy of the latter is generally very poor).

I spotted this in the recent thread about the girlfriend wanting a powerful flash light for her walk-in closet

One potential issue might be the tint, as the current version is a little on the cool side which might make identifying certain colors of clothes or shoes more difficult, but there is supposed to be a neutral version coming very soon...many people are waiting, it seems.

When these sort of statements pop up on CPF I just mentally cringe.

I don't see anything wrong with that statement. :thinking: For example, the girlfriend may have some trouble finding a fuchsia-colored article of clothing if it looks lavender or even deep purple under cool white LED lighting, sort of like in the following example (I grabbed whatever was convenient ):

Sunlight (my ideal reference):

Cool white LED:

Perhaps she could make some mental adjustments in order to compensate, but wouldn't it be preferable to use a flashlight that more accurately renders colors instead?

It is taken as fact that a cool white LED can not render warm colours or allow subtle differences to be differentiated.

They're rendered and can be differentiated, but that doesn't change the fact that they can be way off. In my photo above, you can tell the difference between all of the colors under cool white LED lighting, but the yellow looks pale (almost greenish) instead of slightly orangish (like a school bus) and the teddy bear's fur looks significantly more purplish than it does under sunlight.

By the way, when my filters arrive and I've had a chance to experiment with them, I'll revisit this topic in this thread. At the moment, my unfiltered ZebraLight H51c (4000K CCT, 85 CRI) renders the above subject thusly:

Hmmm...a bit too much yellow in the whites and a little too much red in some colors, but pretty accurate overall (more so than other LEDs I've used or seen to date). I think that a very pale blue or lavender filter--with the right spectrum, not merely the right tint--could make it nearly perfect. :thinking:

 

[Cheapskate]

Re: I'm an LED tint snob!

The colors under solid-filament-based incandescent lighting may be inaccurate due to the spectral imbalance (unfiltered), but it's not any worse at rendering cool colors than cool white LEDs are at rendering warm colors. Also, distinguishing between colors is manageable under both types of lighting.

If you say so.

 

[Derek Dean]

Besides tints, could you please inform us how these Lee filters work for diffusion ?

Most of the tinted filters have no diffusion quality, letting the beam pass unaltered except for tint. However, some of the tinted filters are opaque, giving both tint and diffusion.

Also, there are a large number of semi-clear or white diffusion swatches. Some of them are a kind of thin, papery material, and add a diffusion with a textured feeling, like light filtered through tree leaves, and some are the same type of plastic material that the colored filters are made from, but with varying degrees of diffusion, from mild to quite heavy.

I was just playing with the diffusion filters and found one (HT 254 Frost) that is quite excellent, giving a very mild, beam smoothing diffusion without completely killing the center spot. Very nice!

My guess is that there are roughly 30-40 different diffusion swatches.

Edit: By the way, if you live in Europe or the UK, you might have better luck requesting the Swatch Book from the UK Office:
http://www.leefilters.com/lighting/contact/

 

[GaAslamp]

Re: I'm an LED tint snob!

If you say so.

As a matter of fact, I do say so, at least according to what my eyes see under incandescent lighting. If your photo represents what you see to a significant degree, then might I suggest scheduling an appointment with an ophthalmologist? Kidding aside, I could take photos like that, too, if I used a daylight or other high-CCT white balance setting, but all I'd really be doing is demonstrating the limitations of my camera rather than showing others a reasonable approximation of what I'm actually seeing.

Using the same colorful subject I used earlier for comparison, here is a photo taken under incandescent lighting. To be perfectly honest, I can see and distinguish between cool colors such as shades of blue much more readily in person than in this photo, but they still do show up well enough for me to post this as a worst case example that still supports the point I was making.

And since we're talking about clothing in closets, I went to a closet in my home, picked a random spot that had some cool colors (some of which have subtle distinctions), closed the door, turned on the incandescent light inside, and snapped a photo. As in the photo right above, the colors are not entirely accurate, but the cool ones are distinguishable (even more so in person), and could be identified if you're accustomed to looking for clothes under such lighting (although accurate color rendering makes it easier and is always preferable).

Not that I need to provide one shred of photographic evidence, mind you, as anybody who has ever used tungsten-filament incandescent lighting knows from their own long experience that it's not nearly as bad as your photo makes it out to be (nor mine, for that matter, despite my effort to make them reflect what I see--cameras are not human eyes).

 

[Derek Dean]

Of course the nice thing about using these filters is that you don't have to convince anybody of anything, and you don't have to worry about white balance, or tungsten lighting, or spectral analysis, or anything else.

You don't have to know how to work a digital camera and you don't have to know anything about color.

All you have to do is turn on your light and keep putting different filters in front of it until you find the one that gives you the tint YOU like . For many folks that will probably mean getting it to look more white, but some folks might prefer a bit of pink, or a bit of yellow, or a bit of blue.

Not only that, but if you change your mind down the line and decide you'd like it a little warmer or cooler, all you have to do is cut another filter out and pop it in.

The sky is the limit and their aren't any rules.

Want a purple beam? That's how I got my CPF photo. When I first got these filters I put the purple filter over my flashlight and took a picture of myself :naughty:. It kind of freaks people out when you show them your neat new light and turn it on and it's super duper bright purple :devil:.

 

[leon2245]

I have acquired one since I took those original pics, so here are 3 different LEDs vs sunlight:

Nice!

 

[Cheapskate]

Re: I'm an LED tint snob!

What the camera sees is very relevant, because it gives us an objective view of the spectral balance of a light source. Because our brains are incredibly powerful signal processors, what we perceive is not the same as reality.

The tungsten and warm LED I used have a spectral balance which renders colours poorly, compared to the cool XR-E, which of the light sources I used, gives the closest approximation of Daylight. Our brains are certainly able to process the skewed spectra of tungsten and the warm LEDs and let us perceive colours, but to my eyes/brain, a cooler led gives a better result in terms of colour rendering, probably because less 'processing' is required.

I don't mind people saying they prefer tungsten or warm LED's, but when they say cool LED's can't render warm colours well, they are simply wrong.

Be careful with that argument that your brain can adjust for the spectral imbalance imposed by tungsten and warm LEDs, because it can just as easily be turned around to argue that it can also compensate for discerning warm colours lit with a cool light source.

 

[GaAslamp]

Re: I'm an LED tint snob!

Of course the nice thing about using these filters is that you don't have to convince anybody of anything, and you don't have to worry about white balance, or tungsten lighting, or spectral analysis, or anything else.

Those who care about accurate color rendering do. If all you care about is the aesthetic of the tint, then that's fine, but it's not the be-all-end-all of filtering light.

You don't have to know how to work a digital camera and you don't have to know anything about color.

All you have to do is turn on your light and keep putting different filters in front of it until you find the one that gives you the tint YOU like .

Sure, but without some objective guidance in the process, it would take much longer. Besides, I already like the tints of most of my lights well enough (except for one really green LED)--it's their color rendering that leaves much to be desired. I'm not sure how much filtering could help most of them (while keeping light loss within reason), but maybe I could at least nudge my best one slightly closer to perfect color rendering (and give it a tint closer to that of sunlight).

The sky is the limit and their aren't any rules.

If color accuracy is your goal, then there are.

What the camera sees is very relevant, because it gives us an objective view of the spectral balance of a light source. Because our brains are incredibly powerful signal processors, what we perceive is not the same as reality.

I agree in principle, but what your camera utterly fails to show in your example, due to its limitations, is the reality that there is enough blue in common tungsten-filament incandescent lighting for the human eye (and visual system as a whole) to see "cool" colors and discriminate between them. That was my assertion, it's just as true now as when I first said it, anybody can see this for themselves at the mere flick of a switch, and your photo does absolutely nothing to contradict it (only presents a false representation of the underlying reality).

In fact, I'm pretty sure that your camera would be able to capture and discriminate between "cool" colors (like mine can, and it's not a great camera) if you let it adjust its own white balance, working around its limitations. Otherwise, photos would look as though there were virtually no blue in incandescent lighting, which is demonstrably false (there is way too little blue for accuracy, that's true, but there is enough to see and distinguish between "cool" colors, which was my point). That would make for a closer representation of what people are able to see, which is what most of us, I'd venture to guess, are concerned about.

The tungsten and warm LED I used have a spectral balance which renders colours poorly, compared to the cool XR-E, which of the light sources I used, gives the closest approximation of Daylight.

Cool white XR-Es are deficient at red wavelengths, which makes them just about as poor at color rendering accuracy as incandescent lights (as shown in my previous example). XP-Gs are even worse on paper, by the way, but I haven't bothered to split hairs over which is worse--they're all bad. I will say that cool white LEDs are closer to sunlight when it comes to rendering whites and grays, but that's just one aspect of color rendering.

Our brains are certainly able to process the skewed spectra of tungsten and the warm LEDs and let us perceive colours,

But we can't perceive colors that aren't there to begin with! That would be known as imagination, not perception. Just like cool white LEDs allow us to perceive a skewed version of "warm" colors, incandescent lighting allows us to perceive a skewed version of "cool" colors. You're saying that the latter isn't true because the colors don't show up in your photo, but I say that it is true because I can SEE them with my own eyes and they show up in MY photos (you could suggest that I merely imagined the colors, but I'm reasonably certain that my camera did not).

but to my eyes/brain, a cooler led gives a better result in terms of colour rendering, probably because less 'processing' is required.

And now we finally get to subjective opinion, which is highly dependent on the differences between individuals. If I had to choose--and it's not easy because they're both so awful as well as different in their inaccuracies--I would say that incandescent lighting allows me to see slightly more accurate color rendering overall. This is despite the fact that I MUCH prefer the tint of cool white LEDs when illuminating white and gray objects. However, colors just look so bluish and greenish under cool white LED lighting, while my eyes are better able to compensate for the equally--but oppositely--skewed color balance of incandescent lighting. Maybe I'm just more accustomed to it, but the difference is not great, in any case--both types of lighting are suitable for distinguishing between colors and identifying them (with some effort for some colors), even though accuracy for both is poor. Those who think that cool white LEDs cannot render "warm" colors are mistaken, and likewise those who think that incandescent lighting cannot render "cool" colors are equally mistaken.

I don't mind people saying they prefer tungsten or warm LED's, but when they say cool LED's can't render warm colours well, they are simply wrong.

Where we differ is that I think incandescent lighting renders "cool" colors about as well as cool white LED lighting renders "warm" colors (i.e. poorly but adequate for most practical purposes). This is partly because the spectra of both are continuous, whereas with typical fluorescent or street lighting, to name a couple of examples, we may have great difficulty with certain colors.

Be careful with that argument that your brain can adjust for the spectral imbalance imposed by tungsten and warm LEDs, because it can just as easily be turned around to argue that it can also compensate for discerning warm colours lit with a cool light source.

Where did I ever say otherwise? :ironic: My basic assertion was (quoted from my first post on this subtopic): "distinguishing between colors is manageable under both types of lighting," which referred to cool white LEDs and incandescent lighting. By the way, this includes whatever automatic processing goes on in our heads and in most cameras if you let them do it. The fact that it doesn't work in your "objective" photo that was supposed to capture "reality"--but could NOT because of your camera's lack of dynamic range--is neither interesting nor relevant to my simple, easily verifiable assertion and the reality of human perception.

 

[Derek Dean]

Re: I'm an LED tint snob!

My point with this thread wasn't to use filters to create a perfect color rendering light source, but only to share with other CPF members an inexpensive, easy, and completely reversible way to change the tint on their lights to virtually any color they want ..... warm, cool, pink, yellow, amber, red, etc.

I've read so many threads recently where folks talked about how much they liked everything about a new light they had recently acquired EXCEPT FOR IT'S TINT, and I felt that this was a wonderful way to help those folks change that one aspect of their light to make it perfect FOR THEM.

When asking manufacturers why they don't do a better job of picking their LED tints, I've heard the same answer over and over and over. "Oh, tint is such a subjective thing. What I think is a good tint might not be good to your eyes, so there's no point in worrying about it".

Well finally we are no longer held captive by a manufacturer's choice of LED tint bins. We now have the power to make our wonderful lighting instruments produce the color light that is perfect for OUR EYES, and it won't require a soldering gun or trying to figure out which tint bin is right, it only takes holding these little filters up to the light, selecting the one we like, and then cutting it to size.

What could be easier?

 

[samuraishot]

That's how I also understood as the reason you started this thread :thumbsup:

 

[GaAslamp]

Re: I'm an LED tint snob!

My point with this thread wasn't to use filters to create a perfect color rendering light source, but only to share with other CPF members an inexpensive, easy, and completely reversible way to change the tint on their lights to virtually any color they want ..... warm, cool, pink, yellow, amber, red, etc.

I understand that.

What could be easier?

Taking this quote slightly out of context , for one thing just flat-out saying that expanding the subject beyond the narrow scope you defined is unwelcome. If that is the case, then I will respect your wishes and refrain from commenting on anything outside of that scope in this thread.

 

[samuraishot]

I just got my book of filters from Lee. I did a quick test using an XPG R5-1C and just quickly flipped through the colors and it's neat how things turn out.

If I understand the instructions correctly each filter has a page of information that includes the percentage of light transmitted by each filter.

Be careful though, I tried it out with a Moddoolar triple head with XPG R4s and some filters can't take the heat too well and warp within a few seconds (on high, of course). The good thing is that they also have filters that are High Temperature grade.

Try it, it's fun!

:thumbsup:

 

[Diablo_331]

I just ordered two of the booklets to play with. They were pretty cheap.

 

[samuraishot]

I just ordered two of the booklets to play with. They were pretty cheap.

Did you use the discount code to get one for just a penny?

 

[brembo]

7 bucks for two books shipped, nice.

I use a calibration DVD to get my displays on the proper temps, called Avia Guide to Home Theatre or something like that, search Avia if it interests you. The DVD came with strips of filter that you hold up and match flashing bars within bars so the flashing bits vanish. Calibrated displays look odd at first, as most displays come with hugely overdone reds. Now with this Lee filter book I can dial out the blue in my XM-L lights and make em closer to pure white.

 

[Derek Dean]

I just got one of the $31 Fenix LD01 SS lights yesterday (what a nice deal from Tool Nut), and like everybody else mine had a greenish cyanish tint, but it only took me about half an hour to figure out the right filter, cut it to size, and stick it down over the front glass (the head is sealed).

It's neat that if you're really careful and take your time you can cut the filter so that it doesn't even need any adhesive to stick to the glass. It just kind of sticks down in there against the sides.

Now it's got a nice slightly creamy warm tint...... lovely.

 

[Diablo_331]

Yea I used the discount code. I hope I can make these work.

 

[Derek Dean]

Re: I'm an LED tint snob!

Taking this quote slightly out of context , for one thing just flat-out saying that expanding the subject beyond the narrow scope you defined is unwelcome. If that is the case, then I will respect your wishes and refrain from commenting on anything outside of that scope in this thread.

Sorry,I meant to respond to this earlier and got distracted.

I see you're a new member (welcome by the way), so maybe you didn't realize , but we do try to stay on topic in these threads, otherwise they tend to ramble all over the place.

I think it would be more appropriate if you were to include in your discussion, how to use the Lee Filter Swatch pack to achieve better color rendition with the various LEDs, and in particular precisely which filters you are using with which LEDs. OR, if it's even possible to use these filters to achieve near perfect color rendition, and at what cost in brightness.

For instance, when I recently got my NiteCore IFE2 with an XP-G R5 cool white LED, I found that the filter from page 90 (a medium orange color) seemed to work best to give me excellent color rendition and a very slightly warm tint, AND I found that same filter worked best with my new Fenix LD01 SS XP-G R5 cool white LED as well!

So, for folks having lights with an XP-G R5 cool white LED, you might use the filter found on page 90 as a starting point for your tests.

Anyway, my intentions weren't to stop your discussion, but merely to steer it back towards the original topic of using filters.

 

[Diablo_331]

Re: I'm an LED tint snob!

I received my two booklets today and have spend the last hour or so trying out different filters with my Peak Eiger. I found a few that I like but will take Derek Dean's advice and sleep on it until I start cutting. I also tried the filters with my SC51c and I didn't see anything that made it any better IMHO. Have you played around with your SC51c and the filters yet Derek Dean? I would really appreciate some feedback if so! Now I have an entire 96 hours to mess around with it some more.

 

[leon2245]

Re: I'm an LED tint snob!

I understand that.



Taking this quote slightly out of context , for one thing just flat-out saying that expanding the subject beyond the narrow scope you defined is unwelcome. If that is the case, then I will respect your wishes and refrain from commenting on anything outside of that scope in this thread.

DEfinitely not, this thread was getting interesting!