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16

Red light preserves your night vision. Red lights are used in photography dark rooms, military bunkers, submarines, and anywhere you might find yourself working in the dark. It gives you light to see, while at the same time keeping your eyes adjusted for the dark. I use my red light mostly when I'm when I'm around a camp fire, in the middle of the night ...


10

I would guess it's a carbide lamp as it was in former times used by mining workers and is still used in speleology (caving) sometimes. The basic working principle is a box with carbide and a water reservoir from which water slowly drips onto the carbide. Carbide and water chemically react and form acetylene gas which is guided through a hose to a small ...


8

The automatic f-stop mechanism (iris) in your eye is less sensitive to red light than the shorter wavelengths. Therefore, red light provides some illumination, but doesn't trigger your eye to stop down and make you temporarily blind when you shut the light off. There are also other ways your eyes adapt to ambient brightness that are also less sensitive to ...


1

Night vision and, if you're camping with a partner, a nice way to not blind them around camp.



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