Continuing the theme of M* at 400mm, here is M101 from last weekend. Shot with a T1i (500D), a Canon 400mm f/5.6L lens on a clock-drive (non-guided) mount. I fed DSS with 40x30sec subs, of which I believe it kept 35 or 36, so ~17-18 min of total exposure time. Darks, Flats, and Dark Flats were also applied, but no bias. Final processing for levels and contrast done in Canon DPP. As you can see in the crop, my polar alignment wasn't as good as I had when I was doing M51 a couple of weeks ago.
P.S. Does anybody know what that blob about 10:00 from M101 is? Neither of the astronomers at the place I go knew off the top of their heads.
This is the full stacked frame.
And this is the cropped version that I'm calling my "Final".