Topographic rendering of an image of the Horsehead and Flame nebular region The two very bright stars are Alnilam (upper left) and Alnitak (above the flame) that are part of the belt of Orion. Note that the Horsehead appears as a depressed region as it is a dark nebula while the bright Flame is raised.
Details
2011-02-01 in backyard Victoria BC
Conditions - +2deg, clear with poor transmission and no wind.
Equipment - Orion ED80T CF refractor, 0.8x focal reducer/flattener, modified Canon T1i camera with Ha filter and Astrotrac Travel mount.
Exposures - 26 4 min lights, 11 darks and 8 flats.
Processing in Images Plus and Photoshop