I took only Ha exposures for this image:
This image consists of 13x600 min Ha exposures (=2h 10min). You can clearly see the Horsehead Nebula on the right, the Flame Nebula (NGC 2024) on the left and the streams in the ionized gas in the background - which stem from the magnetic fields in the nebula.
I tried to improve the grainy glow of the bright star Alnikat on the upper left, but could not find a good way to mask it, but not the nebula. I.e. every attempt resulted in the nebula loosing a lot of it's detail. The trickiest part of processing this image was to remove noise and to keep detail and a smooth background.