Hi
Last night I took 2 of the longest exposures Ive ever taken of M83, two 17 minute ISO 200 shots with my EOS300d and 10 inch F5.6 scope, using the new off axis guider. Stacked and processed the images with Photoshop, converted them from the original RAW to 16 bit Tiffs before working on them.
http://www.users.on.net/~josiah/temp/m83small.jpg
The air was very moist, water was running off the telescope tube when I started to pack up.