One always must do the Horsehead nebula at least once a year. This is an astrophotographer code requirement, I think. So, turned the DeadCat 250mm f4.5 at the spot this year, not too satisfied. Sky not obeying, autoguider disobeying, darks down right rebelling. But, you get what you get. Anyway one thing did jump-out from the wider than normal look at this thing, the star count to the right, west, of the horsehead is higher than to the east, must be some dark stuff in the way over there.
Specifics; Vivitar 250mm f4.5 telephoto lens, Zwo ASI1600MC-cool
OSC, 11/5min with 12nm
Ha filter, 15/2min
RGB with Baader fringe killer, gain 200, offset 50, temp -20C. Autoguided with Meade 4 inch
SCT on Meade 16 LX200 for tracking. Captured and stacked in Nebulosity, final in
PS CS5 with Carboni tools. Posted image edge cropped and 33% full size.
Clear skies,
Steve