Re-editing Messier 33

09 December 2022

Last time I shared my first attempt of combining h-alpha data with a broadband image and while I still stand with my first edit, I wasn't completely happy with my edit. The most obvious detail was the galaxy core which was a little bit too pinkish for my taste. So the challenge was to retain the good visibility of even the smaller h-alpha regions while preserving a more natural color within the core.

new versus old edit

I am still not sure if this will be my last edit. Eventually, I would have to collect much more broadband data to get a cleaner image, but for now, I think I will leave it with that.

In the remainder I would like to shed some light on the actual edit and the differences in the process from last time:

  • I re-edited the complete broadband and h-alpha data. For the h-alpha, I tried to make sure not to have too much data within the core but rather focus on the little blobs of h-alpha.
  • The color calibration was done with the relatively new spectrophotometric color calibration from PixInsight.
  • Instead of trying to blend broadband and h-alpha data within PixInsight I did the blending within Affinity Photo.
  • For star reduction, I employed the h-alpha data in a method quite similar to the one described by Daniel Nimmervoll.

As last I want to share some screenshots of the actual layer settings:

h-alpha recolor settings
h-alpha blend mode
Intensify settings
Intensify luminosity range mask
Blend mode for clarity adjustment

Full Screen Image