Obviously, astronomy is a hobby that we practice outside and at night. So how do we get around in the dark? With a little light of course. And the easiest type of lamp to use is a headlamp. It keeps our hands free to operate the equipment, and we can point the lamp where we need the light by moving our heads.

Red headlamp

All these headlamps are shine red light, for a very good reason: As you for sure have experienced before, our eyes adapt to the darkness of the night. It takes some time, but it really gives us much better vision in the dark. The moment we would see white light though, our eyes get overexposed and will adapt back to being less sensitive rather quickly.

Red lights do not cause this effect, and hence red lights will not ruin our night vision when operating our telescopes. It is as simple as that!