sharpness of mirrors
Image quality is NOT a function of mirror size.
Light gathering capacity goes up as the area of the mirror or as the square of the radius. So big mirrors show fainter objects.
A perfectly polished 8-10" mirror probably will give as sharp a set of images as a bigger perfect mirror. Why? Atmospheric distortion. That's what all the excitement is about with the oft derided "Star Wars" technology that has yielded multi-meter adjustable mirrors which compensate for atmospheric distortion in the 50ms/adjustment range.
-p