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DimBeam said: I have always used just white leds for my nightly dog walks but I wonder if I am missing something by not using perhaps green or red or?
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Colors for most general "civilian" use are really down to personal preference and how our eyes are adapted/use to.
Now Red (>650nm) will preserve true scotopic human night vision.
But a lot of people (including me) have problems seeing well/clearly under red light.
Green is used for compatibility with night vision
equipment (NOT eyes!)
But green IMHO gives the wrong type of contrast for the countryside greenery - one might be better off with Blue-Green/turquoise/cyan - which will excite/use the green and blue cones of the eyes.
White generally is the most useful "color" - since there are no problems with color rendition/recognition.
However a point missed by many is the intensity and amount of light needed.
Often a seemingly dim white light may be better for outdoors because the light itself does not give too much difference/contrast - which still allows our eyes to see into the surrounding unlit areas.
You've probably well aware of this using an Inova X5 flood type beam instead of the much brighter Xenon light.
Another problem I see for mono-colors other than the sheer color rendition is that they often will be noticed/attract attention - just because they are unusual. Probably the only exception is Yellow/Amber - since that kind of resembles normal flashlights.
I actually EDC a yellow Photon 2 on my keyring - mainly because it has such a long runtime (advertized as 120 hours - and I've had a yellow Photon 1 last me well over 8 years EDC, and the battery still gives respectable power even now....). I seem to see better at lower light levels with yellow - better definition and contrast - and I have walked outdoors in the unlit countryside with just a yellow Photon...... not really recommended but I have done it - it was definitely a lot better than no light.
Because of the lower light levels I use the yellow Photon for close tasks - whereas the Dorcy 1AAA which I also EDC is used for assisting others and finding stuff in the dark (ie: for longer range)
Please take a look at this thread on LED colors and vision -
LED Colors and Vision (pics)