DavidEF
(DavidEF)
10
I know first order reflectors are better. But the spray-paint mirror coating doesn’t work that way. That’s all I was saying. For a first-order mirror, some other option would have to be used.
EDIT: I have a burned out short-arc projector bulb that uses a hemispherical reflector on the back side to recycle backward travel light waves to the front. It has some kind of special surface, probably for maximum reflectivity.