SCT collimation

[Astroblagger]

Hello is my collimation off judging by the pictures as it looks ok at the eyepiece. Been doing abit of lunar imaging and my images always seem to look abit soft. Looking at the pictures it looks fairly central but seems soft out of focus on the lower side? What software can I use to aid to get perfect collimation? 

[NGC 1502]

Are those images from the centre of field of view?   When viewing visually at high power, 200x plus, on an out of focus star in the centre of field of view, how does it look?

If adjustment is needed it’s the secondary you need to work on using the 3 screws.

[Peter Drew]

If that is a correctly photographed image of a centrally positioned star then I would say that the optics are significantly out of collimation.  At that far out of focus even a perfectly looking concentric image can still need adjustment by the time it is at focus.  You need to have the image almost at focus under at least 200x and in good seeing conditions to improve it.  Adjustments will be minute tweaks of the collimation screws.  Most poorly performing SCT's are good ones just waiting to be properly collimated.       🙂

[Same old newbie alert]

Looks like you have thermal imbalance, just needs to be acclimatized... Pick a star fairly bright and fairly high up.. seeing that you have it on a screen you can measure those concentric circles in software.. APT, Al's collimation, sharpcap

[Same old newbie alert]

This image is with APT...

Other tools that can help is a tri bahtinov mask, or if you want to do during the day without waiting for a star the ocal collimator is getting decent press, I have one but untested so far

Edited February 13, 2022 by Same old newbie alert
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