The Horsehead

One of the most iconic nebulas in the sky is the Horsehead nebula in the Orion constellation. It is a dark nebula that obscures the light from the red hydrogen nebula behind it. I wanted to do a deep exposure of this nebula in addition to the M42 in the same area. This area is also covered in beautiful nebulosity with great details and colour.
I originally intended to have a larger field for my image, but due to some mistakes, I needed to crop the image. First, every night, I used the previous nights images to get a feel for the field. Unfortunately, this meant that the field crept slowly to one side. Secondly, since the humidity was so low, I didn't bother pulling out the dew cap. When looking at the images afterwards, I noticed a faint "rainbow" pattern on the upper left part of the image. I realized this was light from the middle star in the Orion's belt shining in from the side and creating the rainbow. The following nights, I pulled out the dewcap and the rainbow was gone. But I had to crop the image to remove the hints of it. I had to drop about 2 hours worth of exposures, leaving me with about 10 hours 20 minutes of good to semi-good frames to stack.
I tried to get as much details out of the Flame nebula to the left. But I had to balance details for noise. And this is how far I got this time around. Maybe later I will try to kick the noise out to get more details.

Tech Details : Pentax K5, ISO 640, William Optics 132FLT w/ WO AFR-IV flattener/reducer (=F/5.6), on a 10Micron GM2000HPS mount. Guiding with QHY5-II with PHD2. 62x10 min exposures. Stacked in DSS, processed in FitsWork, PS and IrfanView.