Just to follow-up -- did an imaging run from 10PM until 4AM on the Elephant Trunk Nebula (IC1396) in Ha. 20 subs, 2x2 binning, 15 min exposures. Imaging at 2500mm produces a serious close up of a target more commonly imaged at short focal lengths. This 6 hour run was fully unattended and included an automatic meridian flip with camera rotation as well as auto focusing on every sub. This was my first attempt at Ha imaging and processing in PixInsight. The results seems decent:
Elephant Trunk Nebula at Astrobin
Charlie