M31, Andromeda Galaxy
Imaging: ST120 achro, Canon 1000D, no filter, no guiding
Subs: 230x30s (1.9h)
Processing: DSS (stacking), PixInsight (post)
(Additional notes below)
This is the same Andromeda image data as the previous two but with two major improvements. First, the images are now calibrated with "flats" which helps remove the natural vignetting that occurs with taking a (rectangular) picture through a (round) telescope. Second, I am now processing in PixInsight. This seems to be the commercial post-processing application that most serious imagers use to process their images. I am pretty happy with the results, especially considering my first pass at this.
BTW: the blue of the larger stars is chromatic aberration (CA). I have a relatively cheap achromatic refractor and those can't focus blue light as tightly. I have to get an apochromatic telescope which won't have this problem but that is a big expense that will have to wait!