The Lobster Claw Nebula in SHO with RGB Stars

This is my deepest and most refined narrowband project to date: the Lobster Claw Nebula (Sh2-157), processed in an SHO palette with true RGB stars. The image represents 43 hours of total integration captured across a month of clear nights, and it’s also the first time I’ve fully re-evaluated my mono workflow in PixInsight—helped along by upgraded filters and a more controlled process.

What made this project special was the opportunity to really lean into masking and curves to isolate cleaner color in both the stars and the nebula. Using PixelMath for the channel mix, NarrowbandNormalization to bring the palette together, and ColorMask-driven shaping, I was able to keep the strong Ha and SII structures warm and coppery while letting the OIII shell breathe with deeper blue tonality.

The final image combines a starless SHO base with a carefully processed RGB star layer, reduced and blended to maintain subtlety and depth. I’m extremely happy with the color balance, detail preservation, and the natural look of the stars compared to my earlier workflows.

This project also became a full evolution of my PixInsight pipeline, including:

• PixelMath-based palette construction

• GHS for controlled dynamic range

• NarrowbandNormalization (no longer using LinearFit)

• Masked LHE for microstructure enhancement

• DarkStructureEnhance for soft definition

• Noise-conscious processing (light NoiseX early, none at the end)

• Proper RGB star extraction, color calibration, and recombination

This has easily been my most educational and rewarding dataset so far.