LED Filters

The drwback of the LED's seem to have always come down to color rendention. So I was wondering. We have red, blue, green, yellow, and IR filters for lights, Would it be possible to come up with a filter that caused a given LED bin to more resemble the color, or lightwave of an incandescent bulb?

Interesting question... but wouldn't it be next to impossible to do that since there is still a range of colors of LEDs? What would work perfectly for a certain TW0J and gave a great incandescent yellowish tint would likely look terrible with an extreme TV1L.

You are correct. Just as different camera filters have different affect upon various film types. Each filter would need to be constructed to an individual bin. I was just wondering if in reality it would be feasible.

Bravo25 said:

The drwback of the LED's seem to have always come down to color rendention. So I was wondering. We have red, blue, green, yellow, and IR filters for lights, Would it be possible to come up with a filter that caused a given LED bin to more resemble the color, or lightwave of an incandescent bulb?

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No. The incan is producing light in a wide variety of wavelengths. An LED produces a narrow, pure, spectrum. They are somewhat able to produce white by putting yellow on blue. If you want a good color balance you might try an RGB setup.

Another thing is, with the limited experience I have, usually the brightness of the LED drops radically with a colored filter in place. Even when of similar colors.

For example, I've tried red, green and blue lenses on the Nite Ize module. With the red filter in place, it's probably no more than 1 lumen total output. The blue is a bit better which is what I expected since the white LEDs are derived from blue LEDs.

I've also tried a yellow lens (taken from a 55mm camera filter) on a Mag. With an incandescent, I got the results I expected. With a Lux III Magmod, I was quite disappointed in the output though it is probably enough for many uses. I was just inspired when 3rd shift did an amber Lux mod.

Overall, I'd have to think that using filters, even of optical quality, would be of very limited practical use with LEDs.

Bravo25 said:

So I was wondering. We have red, blue, green, yellow, and IR filters for lights, Would it be possible to come up with a filter that caused a given LED bin to more resemble the color, or lightwave of an incandescent bulb?

Click to expand...

Amber LEDs seem pretty close to incandescent except they're maybe lacking a bit of the deep reds. You probably can find a set of filters to bring the resulting spectrum close, but you'll end up losing most of the output. Same thing with trying to get colors by filtering a white LED. It makes more sense to just use whatever color you want to begin with.

In theory you should be able to duplicate any spectrum with maybe 5 or 6 LEDs centered around different wavelengths but you'll need a spectroscope to adjust it.

It's also important to remember that color rendition has nothing to do with the color temperature of the light source. Sure, an incandescent may have a CRI of 100 but that doesn't mean that a light source with good color rendering must resemble incandescent light. CRI tells you if you are able to finely distinguish between colors. Whether or not those colors appear accurately has more to do with color temperature and CRI combined. Incandescent and sunlight both have a CRI of 100 but I'd much rather look at something under sunlight. If you really want to improve the color rendering of a regular white LEDs then maybe an array with mostly white but some deep red will certainly help since that's mostly where current whites are lacking.

Another thing I did was I first built a Tri Lux light using 3 RW0H Lux I LEDs. It looked nice, esp indoors, but I figured I'd mostly use it outdoors. At the suggestig of another member, I replaced one star with either an RV1H or an RX1H (honestly, I forget which) and that gives it a bit of a yellowish tint.

Close up on a white wall, it looks funky because you see 2 white partial circles and 1 yellowish circle, but in acutal use where the hostpost it the primary light thrower, it works very nicely outdoors and gives better green and brown color rendition than the 3 RW0Hs did.

Also, if you are considering colored filters on a case by case basis, it might just make more sense to have different lights with different bins for different uses... X0 or W0 bins for indoor use... V1 or X1 bins for outdoor use...

Y0 bins for when you want to match the HIDs of your BMW...

That is what I love about this place. Just a thought i had, and there are a lot of really intelligent people willing to take the time to share their knowledge. I am now much more "enlightened" for the sharing from all of you. Thanks

It's a shame the filters tend to cut down the output so much... As obsessive compulsive as most CPFers are, I'd have a shelf full of 2D Lux III Mag Mods with every available lens!

I think the same problem exist with the new LED light bars on the police cars. when they attempt to put a blue filter on it so you will reconize the car when NOT lighted . when it lights up , it looks very pale as compaired to the clear lens

I've been trying to get a red AA, pushbutton LED for a few months now. I considered getting a white LED, and using a filter, but was afraid I'd dramatically cut my visible output.

Fenix refused to cooperate by putting out a red version, and the Inova X1, which would otherwise have suited my needs perfectly, wasn't offered in red. Thankfully, a CPF member has a solution (red X1 mod). :rock:

Thanks again, Christopher!

He he... no problem.

Also, I think CPF member and Fenix seller extraordinarie 4sevens was selling Fenix L1Ps with different colored Luxeons. Reds and ambers need less voltage so I'm not 100% sure he was selling those but you might ask him what's up with the red ones.

And if you don't mind the 2xAA form factor, Nite Ize is supposed to be coming out with a red 3 LED module sometime this month. I have a minimag clone with a clickie just waiting for them.

I just took lens out of a UV Leak Detection lamp and placed in a old model flashlight and it worked great. Even for a 2D flashlight. I need to find another 4D flashlight that it will fit in to make it brighter. I dont know what it would look like in a LED Flashlihgt yet. If any of you try this get a pair of yellow glasses because it looks better. But green leaves,grass and plants look red under the light. Also black clothes look red.

4sevens is indeed going to be selling some L1Ps in various colors. They look like they'll be great, but since the platform is initially considerably more expensive than the X1 can often be found these days, of course he has to charge more.

If my long-overdue Army College Fund back pay comes in soon, I'll be getting one of his red L1s, too!

I'll probably get a Nite Ize red when they're available, too. I recently got the white version, and while it doesn't have tons of throw, it's not a bad general purpose light.