Quote:
Originally Posted by alexandre
Hy!
Thank you John, I did not think of finding this kind of defects with the quality optical which we know of Riccardi Honders!!
I am not against a small alteration of the collimation from time to time, but if it remains comparable has my C9, I would go even somewhere else, and can be one 106??
This Tube pleased me for that focal speed , thus has to see!!
Bye ! 
@lex |
To be clear, it's not the quality of the optics or the Riccardi-Honders design, it is the extreme mechanical collimation and tip/tilt sensitivity at F/3 that requires a steady hand. Once those are locked in, you have an excellent system. Fortunately OS provides crude but effectrive tip/tilt adjustment for the camera, and easy to use collimation. What was surprising was that there was a recent apparent mechanical shift somewhere in the optical train. This changed the orthogonality of the camera to the backplate. It was very minor, but just enough to tilt the focal surface leading to the slightly elliptical star shapes.