This is an 8" optical flat mirror. Actual aluminized aperture is 8".
The glass has a tinge to it and I suspect it is some kind of zero
expansion material but I am not certain. Thickness is a generous 1.62".
My folded refractor project never got going. This is a military spec
mirror from NASA. I do not know the surface accuracy however military
spec and NASA mirrors are the best to be had in my opinion. After all
the government is spending tax money and can afford the best. Also I
doubt any optician would put anything but the finest surface on a piece
of glass this valuable. Coating is still very good with some storage
marks a few sleeks and a scratch. Only coating though no glass issues.
Filed under: Eyepieces & Accessories