Does anyone have any advice when choosing between the Surefire m900 lights?  Which color navigation light should I go with and why? White, Red or Blue?
Thanks

Red is a good bet.  It preserves night vision better than any other available color, so you can still use it for small tasks without loosing 50000000 lumens of Surefire light and blowing your night vision.

Quoted: Does anyone have any advice when choosing between the Surefire m900 lights?  Which color navigation light should I go with and why? White, Red or Blue? Thanks

I don't think the LED's matter much as a Civy. Red is generally the favorite choice I think.

I hate the red because you cant have color vision.  Cant see a if a wire or switch is red, green, blue, whatever.  Everything is is essentially black and white.  The white does NOT harm your night vision any worse than the red in my experience.  I have purchased all kinds of LEDs in the past but will only purchase white LEDs from now on because of the color issue.  Especially frustrating trying to look at a map that is color coded with non white LEDs.  I was totally happy with white on my M900.

White light causes the eyes to loose their night vision on varying degress according to brightness. It can take an average of 30 minutes for your eyes to "refill" with rhodopsin (visual purple.) that's the protein receptor that reacts to light and actually gives your rod cells their night vision capability.  It just so happens that green is the best choice for light (think night vision goggles) that has the least impact on the eyes. Red is the next best choice.

Personally, I have red on my Surefire. I have never really used them though, as I prefer to have a tipoff IR filter or just go white light.

Personally, I prefer blue light; it just as effective as red light to prevent night vision loss. One plus of blue light is that, as I discovered in Iraq while serving over there, you can actually see a blood trail with blue light more effectively that with red light.

Don't ask em how I know this.

i like the white lights.

Infared,

You do have nightvision, don't you?

I have the white on mine.  ARKAR

I prefer red nav lights.  Yes, they aren't as good as blue for reading maps, but why would you use your weapon-mounted light to read a map?  Red is better than blue from a scientific standpoint for preserving night vision.  I carry a blue-filtered map light and have red nav lights on the weapon.  Usually I use the SureFire M1 IR light that I have mounted as well though for navigation with my NVDs.

Thank you for all the help.

Why do you guys keep on with the white LED nav lights ruin your night vision BS.  I have em and they dont, period. It is a non issue.  

Quoted: Why do you guys keep on with the white LED nav lights ruin your night vision BS.  I have em and they dont, period. It is a non issue.

Probably because for most of us it does.  People vary in how much it affects them, so perhaps you are in the small part of the bell curve.  From a scientific standpoint though, the white light more quickly dissipates the chemicals that enhance night perception, as well as desensitizing a wider variety of light receptors in your eyes.

Quoted: Quoted: Why do you guys keep on with the white LED nav lights ruin your night vision BS.  I have em and they dont, period. It is a non issue.   Probably because for most of us it does.  People vary in how much it affects them, so perhaps you are in the small part of the bell curve.  From a scientific standpoint though, the white light more quickly dissipates the chemicals that enhance night perception, as well as desensitizing a wider variety of light receptors in your eyes.

No offense, but it sounds like you are just repeating something you've learned in a textbook.  I'm sure it's true and it makes perfect sense, but does it really turn out to be a big deal?  

I really mean no offense, you are sitting in Iraq and I am sitting in my office- I owe you one and don't mean to question you.  

Even if he is just repeating something out of a science textbook, that doesn't mean it isn't true.

I think I mentioned in my post above about visual purple (retinal-ohpsin). That is the chemical receptor that gives you night vision, and is part of your rod cells. Rods outnumber cones by more than 6 to 1 in most people. The eye only sees a few different colors, and uses varying degress of each to respond to shades of others. Kind of like a printer with 3 different ink cartridges.

If you don't get your night vision reduced by white light LED, that's fine. Have a white light AD on most teams and you're done.  It takes the average human about 30 minutes for the rhodhopsin to replenish into the rod cells once they've been flushed with white light.

Blue light doesn't travel as far either, that's another reason people prefer it, especially in the desert. Green light is still the one that effects our eyes the least while still giving us significant ability to determine and "perceive" shade variances. Hence, near infrared spectrum night vision uses green phosphor screens instead of white or red.

As a pilot, I can tell you that it is a FACT that exposure to white light significantly affects one's vision more than red light once your eye's have adapted to low-light.  This is a thoughroughly researched area of human physiology.  The eyes contain light receptive nerves called cones and rods.  Cones provide color and distant vision in daylight and do not function well in darkness.  Rods surround the cones and provide peripheral vision in shades of gray both night and day.  Night adaptation occurs in the eyes after approximately 30 minutes of near darkness, after which the "Rods" in your eyes become about 100,000 times more sensitive to light.  

Red light preserves night vision but interferes with one's ability to distinguish colors.   Exposure to white light on the other hand, even briefly, results in an immediate desensitization of the rods that will not be recuperated until another 30-minute period of night adaptation.

Does this affect your decision to purchase an M900 with white or red lights?  Probably not.  In a tactical situation, you are probably using the main lamp intermittently in addition to the LEDs so your night adaptation will already have been affected.  Pick which ever one you like best.  I'd go with the white LEDs simply because I want usable light at a low power drain when not using the main lamp.  I'm not police or military though, I would expect they would prefer red.

I was trying to make the point that even if it's true and in a textbook, does it reall matter in this situation?  I understand how the eyes and night vision works but explaining how it works doesn't necessarily mean that a 10 second flash of white LED light will change the chemicals flowing in and out of your eyes.

I was looking at the practical real world aspect of what the chemicals do- whether they can change enough to matter in the short amount of time you will spend each time you look at the map, etc.

Quoted: I was trying to make the point that even if it's true and in a textbook, does it reall matter in this situation?  I understand how the eyes and night vision works but explaining how it works doesn't necessarily mean that a 10 second flash of white LED light will change the chemicals flowing in and out of your eyes. I was looking at the practical real world aspect of what the chemicals do- whether they can change enough to matter in the short amount of time you will spend each time you look at the map, etc.

The practical, real world answer depends on what situation you expect yourself to be in.  A short bust of bright white light, even a few seconds, is enough to significantly reduce your eye's sensitivity once night adaptation has been reached.  If you were to use the white LEDs to read a map, you would have significant impairment compared to someone reading with red LEDs because the reflected light would in fact be bright.  If you are using the white LEDs for mild general lighting in a dark room, you're probably OK.  The moment you spot beam someone in the face, you're night adaptation will diminish anyway.

I would go with the white LEDs for my uses, red if I were military.

I am not sure about nav lights but white light will kill night vision, I have not read it but I have experienced it and know it to be true. I choose blue for my lights because, as stated before, it will make blood pop out at you and I just plain like blue. Green might be better, I dont know as I have never used a green light, and I have trouble seeing under a red light, thats just me.

As for weapons lights, if you have NODs, go with IR.

I went with blue nav lights mainly because our swat guys have blue and pretty much identify them as "friendly" on a scene for the most part. Since I'm on patrol and will be first responder a lot of times and may already be deployed with my rifle I don't want to have SWAT doing judgemental shoot/don't shoot drills with me as the shoot/don't shoot target.

I'd prefer green or red for personal use though...

I have the white LEDs on mine and they work great.  However, I prefer the blue.  Just my personal preference.

If you're using white light as nav lights, the aspect you should be thinking about is how much of a target are you making yourself into. Sure, they have some effect on night vision, beginning at the first moment you turn them on. Red light doesn't travel as far as white light does, especially from those size LED's, but why take the risk?

I have a novel idea.  How about using one red LED and one green LED.  That way, in darkeness unfriendlies would mistake your M900 for the nav lights on a boat.  Pretty tricky!

Red right returning? You could use corresponding chem lights to mark those checked vs. unchecked areas of the house too.

I have blue on mine.  I got them because I got a good deal on the M900.  If I could do it over again I would go with the yellow/green combo.

Red being the best for night vision...yellow/green is the next best thing.

#1 you can read color maps with it
#2 it's the next lowest on the color spectrum as far as harming your night vision

Thus the reason Surfire states it's the most popular choice for aviators...being one myself...I carry a Surefire A2 Aviator with the yellow/green LED's and it's great.

Quoted: i2.tinypic.com/qqpwd4.jpg

Is it wrong to really dig that pic?