Search the Community
Showing results for tags 'abberations'.
Found 1 result
Hi everyone. So I'm interested in grinding my first mirror and building my first telescope. I've been reading all that I can about telescopes and watching videos on YouTube. What I want to make is what would probably be best described as a Nasmyth Cassegrain style telescope. My initial idea is to use a 12 inch parabolic primary ground to a focal ratio of 15 and a flat secondary. With a 15 foot focal length the end result will be approximately a 9 foot tube, which is fine, that's actually what I want. I don't care that it won't fit in the trunk of my car, it's not an issue. After reading some articles I've learned that most Cassegrain style telescopes use a convex secondary and a steeper curvature on the primary. Would this be better? Would aberrations be worse with a flat secondary? I want as sharp of an image as I can get without sacrificing either aperture or focal length. It seems intuitive to me that a faster primary would result in a poorer image than using an f15 with a flat secondary...thoughts?