Diagonal Telescope

My new telescope has piqued my curiosity–More specifically, why is it that when looking into the eyepiece we don’t see the cross shaped mount for the diagonal mirror (or the mirror itself?) in the image? I can’t get my head around the problem and it’s been so long since I did optic physics that I’ve [...]

I have a Meade ds-90 with a broken diagonal mirror and don’t know where to find a new one. Would any mirror do or does it have to be a specific one? Sorry, I’ve never owned a telescope before and have no idea what’s what! How do I know what size to get? Which hole [...]