Need help diagnosing this issue and recommendations on a solution. My WO ZS61 is not producing tight round stars. The scope was bought new 1 year ago when I started astrophotography. As a beginner, I didn't notice how misshapen the stars are on the ZS61 until I upgraded to a GT81. I've looked through the history of the images I've taken with the ZS61 using DSLR, ASI533 and ASI 183MC Pro and the defraction pattern is present in all of them. Do I have pinched optics, collimation issues, both? Is there a DIY solution or do/can I send back to WO to fix? The image is a tight crop of one sub that has a minimal stretch.
Thanks for your thoughts and clear skies.