My first attempt at the Horsehead nebula (faint, lower right quadrant). It's a dark nebula seen due to being back-lit by hydrogen gas that is glowing red. The bright star is the left-most star in Orion's belt. The obvious nebula on the left is the Flame nebula.
The Horsehead Nebula is more obvious in the larger view - click on it.
I shot 75x 30 second exposures at ISO1600, with a Canon T1i DSLR on a 190mm Maksutov Newtonian telescope. I tossed out the worst 25 exposures leaving 50.
I stacked it in Deepsky Stacker with a master dark frame. Then since I didn't use flat frames, vignetting was levelled out in Pixinsight. After stretching it back in DSS, the dark structure of the nebulae was enhanced, and the image sharpened using Pixinsight 1.7.
It's pretty crude, and over processed to try and bring out the faint Horsehead nebula, but I'm happy that I could detect it with a stack of 30 second exposures. It's not visible in the individual raw exposures, even the Flame nebula is just a faint smudge before stacking.
The red glow around the horsehead nebula is Hydrogen Alpha emissions, a shade of red that is mostly filtered out by stock DSLR cameras, I'll need longer exposures to make up for this.