I started astrophotography about 8 months ago. One of the first targets I ever imaged was M1 with my trusty little Askar FRA400 on the 533mc pro with an L-Extreme filter. Right out of the box the colors came similar to the famous 2005 Hubble image, but not quite. Obviously I was extremely under sampled at the time for such a small target with a small refractor. But I was still mezmerized and fascinated by what I saw coming through my ASIair.
Fast forward 8 months later, and now I am running a monochrome setup and an 11 inch SCT and ample focal length to sample this target better. The idea for this final image came thanks to the many available tools now for dealing with narrowband color assignments in Pixinsight. The original Hubble image released in 2005 had a very odd color assignment. It assigned Oiii to Red, Sii to green and Oi to blue. Not sure what drove the color choice at the time for the original team that processed that image, except perhaps for aesthetic reasons. Source and details for that image here:
https://esahubble.org/images/heic0515a/I attempted to mimic the colors, but the lack of an Oi filter available to me was a challenge. Ultimately I assigned Oiii for Red, Sii for Green and Ha for blue, since Ha band had the closest frequency to Oi. After adjustments with NBnormalization tool, it seemed to yield the closest results to the original image. I have many other wacky looking versions. SHO / Foraxx and I even used the NB colomapper from Adam Block and Mike Cranfield. M1 is a perfect choice to test that tool because all 3 layers of Sii / Oiii / Ha have unique details and a strong signal.
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