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Coma error


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Hi all. Hope you're keeping safe. Tried using my SW 200P last night with a coma corrector/Canon 650D/HEQ5 pro/APT/PHD2 and results at set up were terrible as you can see. Is this something to do with the optics or polar alighnment error? The PAE in PHD2 was over 11 arch sec with the weight of the tube. Is this the fault or do you think it's something else? I quickly switched to my SW ED80 and the results were far suppierior. Now I need to work out how to add a 2x Barlow when the camera is attached directly to the flattener and the FF screws straight into the tube. Any ideas on that will be very welcome too.

Pinwheel.jpg

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Hi. 

If the telescope is collimated and the cc has the correct spacing, then the camera to cc assembly looks to be tilted. Make sure it's square in the focuser; sw focusers are renowned for this problem.

Cheers and yeah, keep safe.

 

Edited by alacant
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Thanks. I kept thinking the fact that the distortion is only on the right could mean a problem with the focuse tube but I wasn't sure. I'll give it a look next time we have a clear night. 😉

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As I remember the SW coma corrector comes with a replacement focuser insert - this ensures a much snugger fit and minimises possibility of tilt. So assuming you have that correct, it looks like basic collimation. Have you tried an image without the CC?

As mentioned others mentioned above need to ensure everything square before doing up thumbscrews.

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