I have always liked this subject. This is M81, also known as Bode's Galaxy. I photographed it four years ago on a bad night, and what could go wrong did go wrong. The dark frames were not dark due to a light leak. The flat frames just didn't work. I processed the data to the best of my ability at that time, and you can see the result below in this gallery.

Today I tried again, using some new techniques I have picked up. It still isn't very good. The biggest problem I see now is that I did not "dither" the exposures enough when I acquired the data, so there is fixed pattern noise visible as vertical stripes in the image. But I still like this subject, and I am posting this attempt at re-processing the old data. I need to get around to imaging M81 again before long.

This image was created from 42 three minute exposures acquired with a Canon Digital Rebel XT at ISO 400, along with 23 dark frames acquired on different nights. All image processing was done in PixInsight.