Making Red Lights for Astronomical Observing

Mike writes “While LED circuits are pretty simple by Make standards, they are essential to amateur astronomers. This is because red light affects the human eye less than other colors, allowing astronomers to see their gear without destroying their night vision. This article shows how easy it is to create red LED light sources and give some examples of how to use them, including map readers, flash lights and interior lights for an eyepiece case.” Link.