Coma Berenices star cluster aka Melotte 111. This is a stack of 4 x 6 minute exposures at ISO 1600 with the Canon 7D on the TMB 92mm apo refractor with Borg 0.85x reducer/flattener for f/4.5. Taken on a slightly hazy night, April 22, 2011 using AP 600E mount and SG4 autoguider.
The Amazing Sky 