I've had several miserable failures at trying to image the Helix. The closest I got was this nasty one here
http://www.flickr.com/photos/10090242@N03/7961830442/ which despite accumulating more than 6 hours worth of exposure showed no Ha response and lots of noise due to an unmodded DSLR and a light polluted sky.
Well 6 hours and 40minutes worth at Astrofest provided the result I was after. Finally a picture I'm happy with.
10min subs on a QHY10 through a Celestron C8 @ f/6.3