So, I happened to randomly look up “reticle” and Wikipedia, then I got thinking… I’ve already thought about this before. Are gun sights a good place to look to for inspiration on creating a cheap camera viewfinder? Earlier, I concluded the answer was “no” because the primary purpose of a gun sight is to focus only on a narrow center target, but for a camera, you want to know the full details that are in the field of view. Nevertheless, some of the information is interesting and insightful.
20190212/https://en.wikipedia.org/wiki/Reticle
20190212/https://en.wikipedia.org/wiki/Iron_sights
20190212/https://en.wikipedia.org/wiki/Focusing_screen
Mary Babnik Brown donated her hair for use in the crosshairs of the Norden bombsight. The Norden bombsight was intended to be highly accurate and advantageous over previous designs, but real-world use proved it wasn’t much better.
20190212/https://en.wikipedia.org/wiki/Mary_Babnik_Brown
20190212/https://en.wikipedia.org/wiki/Norden_bombsight