Pacman Nebula (NGC 281, Sh2-184), about 35' across, is an emission nebula in Cassiopeia about 9500 LY away. 15 hours of #NBOSC exposures on 2025-10-03 and 2024-10-28 under Bortle 7 skies from Austin, Texas, rendered in a modified HOO palate.

WO RedCat 250/51mm, L-Ultimate dual NB filter, ASI533 MC camera, ASIAIR Plus controller, AM5N mount. 175 5' exposures stacked and processed in PixInsight with RC-Astro and SetiAstro tools. Final exp and crop in Affinity Photo

Below is my image from a year ago. The additional data and better stretching and handling of the HOO palette improved the result. With my dual NB filter Oxygen III data goes into both the blue and green channel. The blue signal is weaker and noiser so I combine both signals for both blue and green. For many of these emission nebulae the Hydrogen alpha signal is much stronger than Oxygen. Adding a bit of the red channel, into the green channel brings out the Oxygen signal where it would be swamped out in a straight HOO palette rendering. I've started labeling this as a #HOhO palette.