Back when the southern sky was still dark enough to shoot long exposures, I managed to do 3 minute subs at F/2.8 and ISO 400 speeds. Taken sometime in July of 2007.
This was taken with my Meade SN-8 and a modified Canon 350XT. I have three detail views from this. Here’s a close-up of the Owl Nebula. Here’s the detail view of M98. Finally, I have a detail view of a compact galaxy group called, Hickson 50. Those smudges of light are galaxies that are over 2 billion light-years away!