Messier 52 and NGC 7635 (Bubble Nebula)

Acquisition:

Bortle 7 skies
Nikon D5600 camera (unmodified)
ISO 200
Astro-Tech AT102ED refractor, 714mm focal length, f/7
HoTech 2" SCA field flattener (1X)
iOptron CEM26 mount
30s x 484 frames (4h 2m)

Processing:

Siril 1.2.4:

Crop to 4800x3600px
Photometric color calibration
Star desaturation
StarNet:
- separation into stars and background
- background: modified arcsinh and generalized hyperbolic stretches, histogram adjustment, background extraction
- stars: synthetic blue (B=2*G-R), modified arcsinh stretch

RawTherapee 5.9:

L*a*b chrominance/luminance adjustment (to reduce chrominance noise)
Luminance noise reduction

GIMP 2.10:

Luminance curve
Saturation