Dates: Ha: 3, 4 May, 23, 26, 27 July, 1, 3, 4, 11, 20, 21, 22 Aug 2021
OIII: 4, 26 May, 26, 27 July, 1, 5, 8, 11, 19, 20, 24 Aug 2021
GUYS
So I started shooting the Ring Nebula back in May in narrowband after realizing I hadn't shot it since 2018 (before I started using PixInsight!). I was hoping to get some nice detail in the core as well as some of the outer halo. Despite imaging from Bortle 7 skies, my gear delivered!! But boy did it take some doing to process the image! I managed to get an astonishing 32h50m on it
Typically when the core and outer edges of an object are vastly different in brightness, you can do HDR compression (in PixInsight with the HDRMultiscaleTransform tool), but I was getting rather poor results. I consulted Adam Block's videos to see if I could blend a low-stretched version (core) and high-stretched version (halo) together, but I couldn't find anything from him. So I got clever and used a combination of StarNet, CloneStamp, MorphologicalTransform, and Convolution to make a nice soft mask over just the core of the nebula, which I used with PixelMath to place the low-stretched core image into the high-stretched halo image. I'm very pleased that it worked!! It took a few attempts to get the mask right, but I think the result looks as natural as one can hope for when dealing with such large differences in brightness. I've got some previous images of planetary nebulae with similar problems that I haven't posted yet that now I can go back and re-process and hopefully get a nice result!
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