peeb

Hi All, Just wondering if anyone could shine a light on this issue I have. I am getting an uneven field of view as you can see from the attached images, I am getting out of focus stars. If I rotate the camera physically the out of focus stars move to the next corners? My focus in the center of the image is spot on as reported by the Bahtinov Grabber. The camera is attached by the way of a screwed in to the camera extension tube which hopefully runs snugly into the focuser. My scope is a Skywatcher 190mm MakNewt and I am using a QHY8L ccd camera. My scope is polar aligned (Polemaster) and balanced, all housed in a permanent setup. Many thanks in advance. Paul