Ed2000

Thanks Michael. I am using ASI533MC pro with the native coma corrector from SW Quattro 150. The flat is fine in orientation during WBPP in pixinsight. I am thinking whether the oval shape donut can be due to stray light. I did not use any dew shield on my Newtonian.

Dear all, I have changed to a new scope (SW Quattro150 F/4) and tried some imaging. During processing, I have found some odd elliptical donut on the final stacked image. I did flocked the inner surface and covered all light-leaks. Collimated with laser and the stars looked fine. The first image is overstretched to show donut. The second image is a overstretched flat. I do need some help. Any comment and suggestion?

Hello. How’s you latest experience in AsiAir Pro and skysensor combo? Does the auto guide work?