Well, it took me three years, but I finally got enough clear winter nights to image the famous Horsehead nebula!
Barnard 33, commonly called the Horsehead nebula, might be the most famous nebula, M42 notwithstanding. Relatively speaking, this is a dim nebula in Orion’s belt, just south of the eastmost star in the belt, Alnitak. I’ve heard that it is quite difficult to see visually, but my long exposure photography pulled out some phenomenal detail. Over six nights in November, I was able to collect almost 33 hours of data. I waited through the next two new moon cycles, but not another clear night in sight to collect more data, so I decided to just process what I have. Here is a 1×1 crop of the Horsehead,
With this target being somewhat low in the sky for me, I utilized Local Normalization to try to reduce problems from light pollution gradients. It worked remarkably well, even though it took three hours for my computer to normalize the 488 images. Instead of trying to normalize images globally, this process normalizes each pixel according to its neighborhood and a reference image. This lets subframes with drastically different gradients integrate very well, leaving no trace of these gradients in the final stack.
The full field,
The lines going across the image are diffraction spikes from the stars Alnitak, δ Ori, and HIP 26713. The large blue glow coming from the bottom left is also from Alnitak.