Originally Posted by zboss
The army has recently completed testing in which they concluded that its not so much the hue of the color but the intensity. So, you are welcome to use regular warm white light but keep the intensity very low. You are best off using a warm white light at low intensity because you can distinguish colors... like you may need to on a chart... unlike if you used a red or blue light.
The military use of lighting
is well researched and dates back more than 50 years. Mil-STD 1472F is the typical reference.
There is nothing new in the behaviour of the human eye. I do see numerous vendors pushing blue as better than red. I'll let the reader ponder why.
Our adaptation to red light is slightly faster than other colors. But the difference between blue, red and warm white is a second order effect.
The intensity of the light is more critical than color in avoiding loss of night vision. The key is to provide the lowest intensity light source.
Red is preferred over blue because it is harder for the enemy to detect red light over blue. Particularly on sites, optics and hand held flashlights. This is why militaries have used red rather than blue for decades.
Silhouettes and colors are hard to detect under red light. Thats why the bridge watch will often be away from any night light.
Our eyes are optimized to spot threats against a green background. It's why tvs have a pixel ratio of 1 red, 1 blue and 2 green pixels.
The best night light source is actually dimmable warm white light. It's only in the last few years we've been able to make leds that can meet this requirement.
On ships we've always avoided dimmers because they are electrically noisy.
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