M31 wide-field view

This is M31, the great Andromeda Galaxy, with satellite galaxies M110 and M32, photographed under very dark skies on January 23, 2015, from a location near Bishop, CA.  The field of view is about 5.5 x 3.5 degrees.

Traveling as a tourist, I had no heavy-duty astronomy gear -- just my 70-200 mm lens and a regular photographic tripod.  I couldn't take an exposure longer than about 2 seconds without star trailing, so I made 80 exposures of 2 seconds (at 200 mm focal length, f/2.8, ISO 6400 on my Canon 6D) and then stacked them using DeepSkyStacker 3.3.2, with final processing in Photoshop.  I cropped out the corners and edges of the original frame, where the stacking software did not succeed in aligning the stars well.