I took a run at this narrowband target during the last moon cycle. Plenty of Ha and some SII in this region, but very little OIII.
A key processing step was to use Bill Blanshan's Narrowband Normalization technique (see
https://youtu.be/PpIOSSj4L5g for the details). I was very pleased at the script and even with so little OIII signal, it did not overly amplify noise in the blue channel when applying the normalization. I also used Spectrophotometric color calibation on a copy of the image and then extracted these "calibrated stars" with StarXterminator. These added them back into the starless normalized SHO image produced with Blanshan's normalization technique. I was very happy with the color range of the stars produced in this way and will likely keep this as a processing step in future narrowband images where not RGB star data is available.
This image was so dominated by Ha that even after normalization, there were lots of green and yellow tints left. I used Bill's modified SCNR script to reduce the green, settling on a final look that is a modified narrowband. There were lots of choices so color choice is clearly in the eyes of the beholder. Comments on the image and specifically the final color are welcome.
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