guillespiers

Hi! I am having the exact same problem, the only difference is my hyperstar is v4, but the camera (ZWO 071 MC Cooled) and it´s backfocus are the same (17.5 mm). I´ve wasted hours trying to fix coma problems with this setup, but it´s impossible. I took some screenshots from my laptop last night to show how serious my problem is: https://wp.me/a6SKCz-1t8 As you may see, the star (sirius), is perfectly round in the middle, but distorts a lot on the edges. Coma points towards the center of the sensor, from any direction. This is why I´m assuming spacing is the problem. What should I do? How can I make sure I buy the correct spacer? Thanks a lot, glad you solved your problem!