I don't know what the official reason for red vs blue is, but I know up here in Canada's military we usually use red because using a blue light would render the blue Grid Lines and numbers found on our topos invisible. <br><br>Being in the artillery, I've seen some of our Warrant Officers use a half red / half blue filter for our flashlights though I'm sure that was mostly an aesthetic thing, as the artillery colours are red over blue. <br><br>Ironbird

...like I wrote, green is in the fray now...<br><br>Doug, I recall reading that astronomer's article - probably from reading your article previously. No personal experience with green light yet. I think that I understand what he wrote - reading, requiring the use of cone receptors, is driving his conclusions. Based on the data he presents, that makes sense. <br><br>The sidebar article is at least as interesting. The comments about the huge range in individual sensitivity is right on in my experience. I believe that It is very hard for those of us with exceptional night vision to fully comprehend what the night means to others who have very poor night vision, even when witnessing it - "Are you SURE you can't see that..???". Training to use what one has helps but does not improve anyones ability.<br><br>Reading is not the same as basic spatial tasks such as walking, locating objects (packs, firewood, tools, etc.), detecting terrain features, etc.. The Army I grew up in did a superb job training me to use my night vision (actually, I got the exact same training as a boy in the Scouts - I knew the drill as soon as I "saw" it in the Army). For an Infantryman, particularly one with no need to check a map, that was all the training one would ever need. To this very day (night), I reflexivley squinch my master eye shut at the suggestion of a spark of artificial illumination of ANY color or source and only open it after it is cold out dark... usually preserving some, if not most, of my night adaptation in that eye.<br><br>Reading without totally ruining ones night adaptation is an area that the Army did NOT cover with training - just a maxim, enforced as strongly as the commander's personal night vision ability: "Use red light. Do not use anything but red light." OK; fine - that's what I did (and do). Yeah, I was/am death on anything not red if night vision was/is important. I even disliked blackout lamps and convoy tail markers. And even then, NVGs meant even red light had to be completely shielded under cover to avoid detection. But this forum is not about avoiding detection...<br><br>The green argument makes sense as he presents it. The blue "argument" never made sense to me and still does not, unless one is speaking of a blue-green source that is predominantly green. I intend to obtain a green light source and try things out for myself. As you are probably aware, green light reportedly has some peculiar effects when used in an environment heavy with green foilage. I'll draw my own conclusions after I check it out. BTW, I noted that he specifically refered to polychromatic green light - interesting. Still narrowly banded for wavelength, I assume. I'll check the spetral cahracteristics of the LED he suggested using.<br><br>This will be interesting.<br><br>Tom

Another important factor in night vision is a good diet. This can greatly vary between two individuals. <br><br>In my experiences a red photon has been good.<br><br>GATOR

D'OH

I carry a backup Photon II in amber or white in my backpacking kit. When space isn't at a premium, the light weight of the Photon makes it attractive to double up on, rather than carrying spare batteries and messing with the tiny screws.<br><br>I learned from experience that when using a red light at night, it's very difficult to determine whether or not your're bleeding. You can't see the blood. Makes it difficult to find and treat little boo-boos. The white light solves that, at the expense of your night vision.