After practicing a couple weeks with the ASI1600MM-C, I chose the planetary nebula M27 for my most ambitious project so far.
The outer wings of M27 are very faint and difficult to observe, especially from light-polluted areas like my home (SQM ~17.5)
That’s where narrow band filters really prove their worth: I was very pleased to see the outer halo after only 2 hours of exposure per channel while using very short, high-gain subs. (perfect for my cheap mount).
My Ha subs from the second night introduced some star bloat in the stack though and this initially resulted in bright red halos around the HOO stars.
So I decided to remove the stars from both channels, and only used the OIII stars after tonemapping the nebulosity.
I like the amount of detail that’s visible at full resolution. It completely blows away my previous DSLR image.
However, M27 contains beautiful knots around the central star, and I've found it very difficult to bring these out without making the picture look cartoonish or overprocessed.
The core is stupidly bright in both OIII and Ha.
I'm currently using HDRWaveletTransform on the stretched starless images, with a mask around the core and different settings for both channels, before combining them with PixelMath.
Is anyone here that processed this nebula before, willing to share some tips for controlling the core?
Anyway, thanks for looking.