Here is the problem; I am using a ZWO 071 MC pro camera with an ASIAIR Plus control module. I am shooting live and stacking the images. So for, no problem. I save the individual images to my external USB card. Still, no problem. Now when I try to get my flats with a flat light source, I let the ASIAIR figure out the correct exposure because my images are full of donuts. BTW, I cleaned the glass in the camera, but they are still there. Another question to address is the source of these donuts, but back to the problem. I save the master stacked flat images and then try to process them. I use the latest Deep Sky Stacker program ver. 5.1.5. I place both the individual light images and the master stacked flat image and I start the process. After getting the final stacked image, I go to GIMP and try to post-process this final image. And by this time you already know my problem, DSS did not eliminate the donuts. Now to my learned astrophotographers on this forum, what am I doing wrong or is my equipment just swamped out because of the dust donuts. What to do?
