"NGC 253 is one of the brightest spiral galaxies in the night sky, but also one of the dustiest. Dubbed the Silver Coin for its appearance in small telescopes, it is more formally known as the Sculptor Galaxy for its location within the boundaries of the southern constellation of Sculptor. Discovered in 1783 by mathematician and astronomer Caroline Herschel, the dusty island universe lies a mere 11.4 million light-years away. At about 70 thousand light-years across and thus somewhat smaller than the Milky Way, NGC 253 is  nevertheless the largest member of the Sculptor Group of Galaxies, the nearest to our own Local Group. In addition to its spiral dust lanes, tendrils of dust seem to be rising from a galactic disk laced with young star clusters and star forming regions. The high dust content accompanies frantic star formation, earning NGC 253 the designation of a starburst galaxy. NGC 253 is also known to be a strong source of high-energy x-rays and gamma rays, likely due to massive black holes near the galaxy's center." - NASA (abridged)
This galaxy is so active and has such a strong Ha signal that I had to significantly subdue the addition during the Ha enhancement as part of the Continuum Mapping process. In fact I reduced the intensity to about 1/3rd of the level that I normally use, lest the Ha signal completely overwhelm the other details. This is a difficult galaxy to process and when one looks at images on AstroBin and the Internet more broadly, there is a very wide variety of appearances, particularly colour. After a number of itera and much consideration, this is where I landed. As I mentioned, the Ha intensity is subdued, but still sufficiently present, to clearly show how pervasively it is distributed through the galactic arms and where the knots of greater intensity lie. I am pleased that the central core of the galaxy has come through with a warm yellow-orange glow, due to the presence of an older population of stars. The spiral arms are very dusty and the perpendicular tendrils are clearly resolved. The dust somewhat obscures the areas of young, hot blue stars, in the inner parts of the spiral arms, although their colour is more obvious towards the periphery. I tried to reach a colour saturation that doesn't result in too garish an appearance, but still shows the richness and breadth of colour that is so clearly present here. Despite the difficulty in processing this one, I hope I have done justice to its abject beauty.
It is clear that the galaxy is virtually a perfect ellipse, which is the projection of its, no doubt, circular shape, due to our viewing angle. As I've done previously, when you stretch a perfect ellipse back to a circular shape, you can perfectly deconvolve it to show what the circular object looked like face on. Now NGC 253 is tilted a great deal, being only 12 degrees from edge-on or 78 degrees from face-on and that makes the deconvolution less accurate, but it is also a very flat galaxy. I've never done this exercise for a galaxy so close to edge-on. The result is shown in Revision C. I think it really helps to see the structure of the galaxy. For instance it is clear that there are basically two spiral arms emanating from the core. Note that the dust tendrils, which are clearly emanating in an orthogonal direction from the plane of the galaxy, don't deconvolve well, because they are in effect a phenomenon in the z-direction, where this form of deconvolution, only works for structure in the x-y plane. In any case I hope that you find that interesting.