Quote:
Originally Posted by Paul Haese
Just to make things plain boys. I was answering the original question about the stars in the corners. Please in future read the original post.
Just to make things even more clear. Using CCD inspector is not indicative of collimation issues and can be frequently wrong. Several things could be going on here, including guide errors, flexure and tilt. All of which can be solved but the question asked why the stars were elongated in the corners. To which I gave the correct answer of a field flattener or reducer.
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Paul, I was trying to indicate the use of ccdis for inspection of curvature and tilt, not so much for collimation. Yes an FR is needed, but the asymmetric star elongation should be investigated as well. Ccdis is good at mapping that.
It could just be that the camera wasn't seated squarely during testing.