Quote:
Originally Posted by gregbradley
Good guiding and elongated stars seems to be contradictory statements.
The only time I have seen "good guiding" (of course its not good guiding if the result is elongated stars) was when I had differential flexure and I was using a guide scope. So the guide scope was seeing the guide star just jim dandy but the imaging chip was showing drift due to something not being rigid with the guide scope.
If in fact your guiding is good then that only leaves optical movement like the secondary is moving slightly or the primary is distorting slightly.
When you grab these parts are they all rigid? Mirrors, tube, focuser?
See if any move when you push/pull them.
Greg.
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Thanks Greg, It all feels tight, but im out now to measure focuser flexure.
Quote:
Originally Posted by Peter.M
If the primary or secondary move slightly then the guider would register this movement also. It would also effect collimation I guess. If it is only in corners of images then you can rule out anything to do with the guider because elongation would be in the center of the frame too. My money is on the secondary or focuser flexing.
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Cheers Peter, my money would be on them too, the elongation is all over the image as well.