I had just downloaded the Magic Lantern firmware which allows for extra control over Canon SLRs. One of the features is to be able to record video at 4fps at 1/4sec exposures. I gave Omega Centauri a go with the Canon EOS 600D at prime focus of a 12" SkyWatcher Dobsonian (untracked, unguided) and here is the result.
Video:
http://youtu.be/393BliqEoH8
The attached image is all 280 frames stacked in Registax with levels applied, at capture resolution.
Sorry about all the noise.
Tom