Just wandering if anybody has any advice on primary mirror dots.
What colour? Red, White, black?
What size? is the best? or does this depend on the scope?
I have read that you can use a paper ring binder circle? isn't this too big?
Logic suggests that the smaller the dot the more accurate the collimation? such as the tip of a fine felt pen? (as long as you can see the dot!)
An another query is if the dot is too big would it not cause abberrations or a mark in the image quality?
