Thoughts on A2 LED color?

GadgetTravel

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I almost pulled the trigger on an A2 a month or so ago. One reason I didnt is that it had red LEDs. Now Im wondering if I made a mistake. A friend of mine who is a chemist that does a lot of imaging using lasers and now LEDs told me he thought that red would be good for seeing in smoke or fog, as well as maintaining night vision of course. But I guess the general question is, what are the advantages and disadvantages of the various LED colors? Im getting close to getting one of these and am wondering about the LED color. I tried searching, I suspect this has been discussed, but alas, no hits with a search. Any suggestions or comments appreciated. Thanks.
 

WDR65

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White is considered the best for all around use and color recognition. I use white now, but I would like to have a red one to add to hunting bag for walking into my stands in the morning. Blue I think is useful for finding blood as blood shows up black in blue light. Green is supposed to be the brightest overall, but its also supposed to have a lot of artifacts in the beam. The yellow green is good for night vision equipment if I remember correctly. Just remember that most of the colors other than white and possibly yellow green make discerning colors difficult if not almost impossible. I'm sure someone on here with more knowledge in the subject will chime in soon, but I hope this helps a little.
 

beezaur

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I have two A2s, one red and one yellow-green. The reason I don't have white is because I have other two-stage white lights that are LEDs. For me the unique thing about the A2 is being able to have two colors.

Pretty much however you cut it, the LED mode on the A2 is for close-up work, like reading or filling out forms. Color rendition definitely can be a problem with red on things like maps. The yellow-green works surprisingly well, since the spectrum is quite broad for a single-color LED. You actually can make out blues and reds just a little bit, and of course colors in between are much better.

I have found it to be true that red is a better color for seeing through smoke and haze. I have an Aleph 3 with a red-orange Luxeon III that does a great job. But there is a catch: the strange thing about red is that, as it gets less intense, your ability to see it diminishes disproportionately. Both my A2s are about the same brightness close up (in fact the red is a lot brighter for reading). But at around 20 feet, the red light just about vanishes. I see the same thing in the Aleph at around 75 yards. The yellow-green acts like a normal light.

The red A2 is great for stargazing and poking around the house without waking anyone. It is my "bump in the night" light for this reason. It is wonderful when a low-observable low mode and a good throwing high mode is what you are after.

The yellow-green is decent at preserving night vision, still a very soft light. It is a very pleasant light to read by. The notable feature is that you can still make out other colors reasonably well.

The green and blue just don't do much for me. Cyan would be cool though.

Scott
 

davidra

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I've got red, blue, and white. The white is much brighter than any of the colored lights (although I've never seen a yellow/green) and can easily be used for walking at night in most settings. The red is a great indoor light, but with ambient light outdoors it may be a little dim for walking. Remember these are designed for the interior of airplanes, not for spotting with the LED's. All the colors have ring artifacts whereas white doesn't. This isn't a huge thing in actual use. I have the white one in my car (it's an old one, pretty beat up when I got it) and the red one bedside. Other than the wow factor, I've not found blue to be particularly useful. That's why I replaced the LED's with the white ring.
 

Bravo25

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I put a lot of thought into this subject before I bought mine. I finally concluded that if I bought a colored led ring I would have pretty much a dedicated light. So I opted to go with the white, and I use filters when I need a different color.

BTW since this was my first Surefire, and I got it from "Oldgrandpajack" I want to say a quick Thank you to him. John my wallet blames you, but I thank you!
 

KevinL

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One easy way to find out if you like the various colors, or at least the way I did it - I played with them on the keychain lights since they came cheap. I got to see red, blue, and deep green LEDs for a few dollars (for all of them), and eventually I found myself putting them away after playing for a short while. They were never seriously used. On the other hand, white is always useful. My A2-BK only came in white, but that is the color I would have asked for.

Colored LEDs are specialist tools for specialist users. I suppose I can put it this way - if you need them, you will already know that, and know specifically what you want them for.


Bravo25, congratulations on your first SF.. mine's the latest addition to a family of no less than nine Surefires, and I must say that amongst all of them the A2 has the nicest incandescent beam. OGPJ is a great guy to deal with and I have always appreciated working with him :)
 

GadgetTravel

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Gee, back to this. I tried to buy an A2 this past Saturday, and all they had were yellow LEDs so I didnt get it. Any thoughts on comparing the Yellow LED to the white LED version? I think I have it narrowed down to these two. Thanks for any comments.
 

elgarak

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Quickbeam has some explanations on his webpage. Take a look here and here (scroll down on the second link for some explanations on night vision).

In essence, he describes my experiences and recommendations perfectly. The only overall usefulness has white light. Red might be useful for a lot of people in preserving night vision (let's say, for stargazing/amateur astronomy/chemistry [not triggering photo-activated reactions]).

Anything else is highly specialized. It might work, but mostly it's just cool. First try it with filters on a bright white light or with colored cheap keychain lights before you invest in an A2, if you really need the color. Most people just buy colored LEDs for showing off. The usefulness is very limited.
 

beezaur

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I think the yellow (yellow-green) would be more of an unobtrusive/night vision adaption color. You might use it to read in the car while your spouse is driving, get up at night without waking someone, etc. It might be a better light for camping where bugs are a concern (haven't tested that one). White is a better general use color, and more people prefer it for that reason when they want their A2 for general everyday use.

My own philosophy with owning a bunch of lights is that I don't want a lot of general use lights -- that would amount to having a whole lot of the same thing. I like to own a bunch of specialty lights and enjoy each one for its own distinct purpose. I have my general purpose light for EDC, and most of the others are "wierd" in some way (just like me :) ).

Scott
 

hank

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There are several really thorough discussions of night vision in the archived forum posts, worth digging out -- and some differences of opinion about the best colors to use for night vision. It depends a lot on what you're doing, whether you need to judge colors on a map or just not trip over the telescope tripod, while keeping your dark adaptation. Worth some digging. I haven't mastered searching the old archives yet or I'd post links to them.
 

beezaur

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Here is a map by the light of my SureFire L2 on low:
mapl27kj.jpg


And by my A2-YG:
mapa2yg6cp.jpg


Scott

PS: The relative brightnesses are "normalized." The L2's low beam is much brighter than the A2-YG.

Thanks to ImageShack for Free Image Hosting
 
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TorchMan

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The only other thing I can postulate on having yellow-green LEDs in the light is that maybe, just maybe it's easier on the eyes to use if you were already using night vision equipement with yellow-green phosphor. Sorta like going from a room with one color light, say red, and then into another room where the light is red or white. Or taking off BluBlocker or amber glasses and the world looks more blue...

I read years ago the military was going to yellow green phosphor in night vision as most users found it caused less eye fatigue. Maybe the same color soft light from a flashlight is easier on the eyes, especially if that's the color of night vision being used. According to the photos in the post above, Y-G sure doesn't give good color recongnition.
 

leukos

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All colored A2 LEDs have artifacts. I've sanded all of mine to diffuse them better and IMO have improved their usefulness immensely. I own green, red, and white and did own the yellow-green for a while. I like them all. If I had to pick just one though, I would go with white LEDs and stretch an F05 red filter over the bezel so I could have red too. :)

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