[Jason D (Jason)]

Originally Posted by Steffen

You can always achieve perfect collimation by looking at star images in and out of focus and adjusting the mirrors to get as close to "textbook" as possible

Collimation consists of three different alignments:
1- Centering/rounding the secondary mirror under the focuser for optimal illumination
2- Eliminating any tilt between the primary/EP focal planes
3- Eliminating any shift between the primary/EP focal planes
The first two alignments are carried out by the secondary mirror and the last by the primary. Star collimation only takes care of the 3rd alignment. Granted is it the most critical alignment but you can’t achieve perfect collimation without perfecting all 3 alignments. Besides, star collimation is not as perfect as collimation achieved by quality collimation tools though it does bring the scope “within” collimation tolerance.

I'm often fantasising about servo motors at the primary collimation screws and a little hand-held pad for adjusting them while looking through the eyepiece. I'm afraid I'm not handy enough to make that myself – why is there no commercial solution for this?

Apparently someone holds a patent for it
http://www.google.com/patents/US20110116181
But I do not think it is a practical solution.

Jason