[glend (Glen)]

I believe the 'experts' are producing long signal totals through the use of multiple sessions over many weeks, mostly using capture automation to tend to the scope, camera, mount, etc so it can be done unattended to some degree (albeit they are probably in the house monitoring the computer or checking the run from time to time). Plate solving will allow matching of exposures over many nights I believe. There certainly seems to be some sort of pride in the acquisition of many hours, days, etc worth of signal data - all of which has to be processed. To the amateur working with a dslr it seems a very different world.

I recently ran ten, five minute subs of M104, out at Bretti (so fifty minutes of signal data) - which is my longest run to date. Even after stacking in DSS, with darks, flats, offset bas frames, the resultant image taken into Photoshop really didn't look too much better than one single sub.
I suspect my equipment maybe a limitation, one shot colour from a un-modded dslr but still I am happy with what I can produce. If your not interested in the 'competition' imaging world just do enough to satisfy your quality standards.

Now that my observatory is complete and my mount is on a pier I hope to be able to run longer subs then I can make some comparisons