Hello everyone, I recently purchased my first scope which is a William Optics Z61 and also its dedicated field flattener. The first image I took with it was on the Carina nebula. For a first image I am pretty happy with it, but I have found that there is still a lot of distortion around the corners of the frame. Does anyone know if this is an acceptable amount of distortion, or did I get a dud scope or field flattener?
This image is also only about 15 minutes of exposure time, but I would love to hear any advice on how to make my images better
https://cdn.astrobin.com/thumbs/Jvaf...0_wmhqkGbg.jpg