Why using color LED when you can use color glass filter ?

LED Flashlights – General Info
1

I wonder why there is color LEDs when you can plug a glass filter with different color choice that will deliver more lumens than the low output color LED and you will not be forever stuck with only one color choice.
Or maybe I am missing something and the color rendition is better ?

Colour filter for C8 > http://www.aliexpress.com/item/HI-MAX-Red-Yellow-Green-Blue-White-frosted-Color-Len-Filter-Cover-for-45mm-C8-Flashlight/868764339.html
For P60 > http://www.ebay.com/itm/Spiderfire-4-Color-Filter-Set-Fit-for-Surefire-6P-9P-G2-C2-UltraFire-501B-/380379925975

2

You are missing something, namely the fundamental way a LED operates.

An incandescent bulb emits light over broad spectrum of wavelengths from purple down to red and even infrared. When you put a colored filter over an incandescent bulb, it filters out all the colors of light other than that filter’s color.

A LED however emits a very specific wavelength of light and must be tuned to emit a certain color. That yellow pigment on the surface of the emitter is actually a layer of phosphorous that is stimulated by the emitter to produce yellow light as the base LED only produces blue. The blue mixes with the emitted yellow from the phosphorous and that produces the cool/neutral/warm whites you see LED’s advertized as. Colored LED’s use different chemistry in the emitter to produce the different color.

Because only one wavelength of light is emitted, putting a filter over a LED will block almost all of the light.

3

“Special note to yellow filter, it has the most penetrability through frog.”

Does it hurt the frog? :X

4

I don’t understand why it should be different, it output white light containing other color wavelengths.
Do you mean the color will not pure as a red/blue/green LED because some light color will be lost in the glass along with wrong colors passing trought ?
Any real world comparison ? It should be highly dependant of the quality of the glass.

5

A cool white emitter has a color rendering index somewhere around 60 (maybe 70) it washes out some colours because it isn’t generating the full spectrum of light to get white light (not equally)
An incandescent light has a cri (colour rendering index) of nearly 100. So when you use a filter on an Incan you only lose 20-30% of your emissions.
With an led you lose close to 80% of emissions

Losing 80% means a 300 lumen flashlight with a red filter is only giving you 60 lumens of red light.
A red xpe2 at that same drive current is giving you over 110 lumens of red, nearly double.

Does that make sense?

6

My numbers aren’t perfect but it’s Monday and I’m groggy

7

XP-E2 are rare and pricy and if you want 3 colors blue/green/blue it will cost you $90 from the P60 drop-in I have found.
The more common P60 XR-E blue/green/red at $6.6 each will cost you $19.8 so about the same price as the filters but you lose the yellow and frost lens.

A XML2 T6 Neutral White at 3A will output more than 1000 lumens at typical 75 CRI so even if you loose 80% (but even less with NW) it will give 200 lumens of red/blue/green light so twice as the XP-E2.

And the XP-E2 are not rated at high output so it will most likely burn them or greatly reduce their lifetime. The old XR-E are even weaker.

But yes you will loose alot of power resulting in heat on the glass but on the other hand you can unplug it any time.
The only thing is that for long runtime use it might be better for your battery to have a color LED.

Someone have used and compare both of them ?

8

If you genuinely think there exists a P60 that produces 1000 lumens, or that there is any available C8 that produces that amount of power out of the box, then you clearly need to do more reading. Furthermore, NO XM-L will produce 1000 lumens at 3 amperes. According to Match’s emitter tests a XM-L driven at 3 amps will generate 880 lumens, at the emitter. Figure in reflector and lens losses and you only have 150 lumens at best, and that’s assuming the 80% figure is accurate.

And there is relatively little heat put out the front of the light. Most of the heat that a LED generates is from the current passing through the emitter, hence why there’s such emphasis on properly heat-sinking the emitter.

9

Sry, but you are simply wrong.

Have you ever seen a relative spectral power distribution graph of a XM-L2?

You will loose more than 80% of the lumens with coloured glass!

These pages might you help to understand:

http://www.vision-doctor.co.uk/coloured-light-coloured-objects.html

http://www.vision-doctor.co.uk/colour-filters.html

Why should anyone use an XM-L2 @3A if you will get more coloured lumens with a special colour LED @750mA and 4 times more runtime?

10

I have a Sunwayman c21c and it has a red xpe2, the thing is all flood but incredibly bright. The xpe2 red has its benefits but it’s not a huge improvent over its xpe predecessor. Copper mounted it is a nice improvement.

There’s also an RGBW MCE dropin made by VinhNyugen if you want all four colours without having to swap lenses or diffusers

Running an XML with a diffuser may trap in heat.

Long story short, there’s different ways to the store, you got to look at what’s right for you in the categories of : Brigtness needed, runtime & heat management, flashlight or dropin, quality of tint, and whether the light is just found one job or multiple lighting uses.

For me I don’t need multiple colours, I like having them. So runtime isn’t important but colour quality and consistency is, so I go emitter most times. The diffusers often let me down.

11

That was my rough guess, by eyeballing, my apologies. The light loss is substantial

12

The MCE-E RGBW is awesome but outdated. It is better to use the XM-L Color LED with the MC-E Color Driver!

Here are the parts to build a Dropin:

http://intl-outdoor.com/cree-xml-color-led-16mm-mcpcb-p-724.html

http://intl-outdoor.com/mce-color-and-dynamic-white-17mm-driver-p-686.html

I would prefer this about any colored glasses.

13

For evenings, I use lights that don’t emit in the 400-550nm range (which affects the sleep cycle, particularly for babies and older people): http://ehp.niehs.nih.gov/119-a472/

So we use mostly amber LEDs (widely available as “turtle-safe” lighting, you know how to look this stuff up (grin)).

I also use color filter gels over ordinary light sources.

LEDMuseum is a wonderful resource (it’s one quirky guy on disability so contribute something if you find it useful; he’s been a reliable source on the Internet since before it got the wwws.

http://www.ledmuseum.candlepower.us/eighth/l15way25.gif (amber)
http://ledmuseum.candlepower.us/twenty1/sst-90.gif (emission spectrum for a “white” LED, mostly blue)

Remember “white” LEDs are, like “white” fluorescents, actually a blue-range emitter, under a fluorescent material.
That absorbs the high energy blue photons and emits somewhat lower energy photons.

The emission spectrum isn’t the same as the color temperature — a “warm white” LED has somewhat more emission at the warm end but still has a lot in the blue. The very newest warm white emitters are supposed to be using a green emission to drive the phosphor, and so be safer when used in museums on old paintings for example where the blue light degrades the material over time. http://www.pbs.org/wgbh/nova/charters/fading.html

Here’s a white LED with a flaw in that fluorescent layer — see the blue-violet streak?
http://www.flickr.com/photos/wossname/3201800207/

here you can see the flaw in the phosphor:
http://www.flickr.com/photos/wossname/505251021/

So take that “white” emitter and overlay a filter gel of your choice
http://www.rosco.com/filters/roscolux.cfm#colors

Click the little icon next to a filter, to see how much of each wavelength is transmitted by the filter, e.g.
http://www.rosco.com/filters/SED.cfm?titleName=R14:%20Medium%20Straw&imageName=../images/filters/roscolux/14.jpg

For anything in the green-to-red range, filtering out the huge blue part of the emitted spectrum wastes all that energy.

Aside to all, I’m always interested in ways to change LED lights to amber emitters (remembering they use lower voltage than the “white” emitters). One way is to add a resistor but that wastes energy. Another way is to have a driver that measures the current flow through the LED and adjusts it — but it’s hard to find them documented. Pointers always welcome)

14

I was using CREE numbers. We have little info about lights, almost everything is based upon manufacturers data.

I used light with my anaglyph 3D glasses (red&cyan) and the results is not that bad that why I ask about color filter, loosing maybe 80% of light and the glass get hot.

All that theory is good but have you compared color LED and a XML light using color glass side by side ?

What do you thing of this P60 drop-in ? Claimed 250 lumens. So under 100 lumens in reality I guess.

Thanks ! This must be awesome to use !

15

Then you should go that route, I wouldn’t go with “spiderfire” diffusers.

You may want to get a diffuser to make the beam floody, as the beam pattern off an RGBW quad die emitter will appear off centre in the individual colours

16

Match and a handful of other BLF and CPF members have actual calibrated light spheres to read Lumens OutTheFront readings.

As for blue emitters, with out a tailcap amperage reading I don’t know how bright that blue dropin will be.

I really like red emitters, I don’t use blue LEDs as the light is hard on my eyes and gives me headaches almost as quickly as uv light dropins. (I have two uv dropins and love em)

The blue will look noticeably brighter than the red at the same drive current as there’s less phosphor infront of the die to get the desired colour

17

It’s all been covered already, but I would point out that the Sunwayman C21C uses a red XP-E (gen1) P2 rather than an XP-E2. Not that that makes any real difference functionally.

18

So it does, dang so I still don’t own a red xpe2. Thanks for clarifying RedForestUK

19

I own a Nailbender SST-90R Dropin!

If you are searching for a red light, i would prefer one of these Dropins.

These LEDs are the most powerfull colored ones for flashlights.

http://www.luminus.com/products/SST-90C.html

The amount of red light (ca. 360 lumens @3,04A on Turbo) is not reachable with a red glass lens in Front of a XM-L2.

The steps should be around 25 - 70 - 200 - 360 lumens.

SKYRAY King on High ca 2000 lumens.

20

XPE2 is only available from mouser etc., so rather expensive. But they are not THAT much better than the old XPE.

SST90 in red is cool.. but really expensive. :D