While I have done better images of the Orion Nebula, this one is from a stack of only 3 - 30 sec exposures. I used to expose for an hour to get something that is equivalent. The Canon 6D full frame camera is pretty sensitive.
02/20/2015 02:44:20 UT at the Alberta All Star Party near Rodeo NM,
Canon 6D (modified) on WO 105mm APO with HEQ5 mount.
3x30s at ISO 640
Processed in ACR and Photoshop