NGC 6939 and NGC 6946 (Fireworks Galaxy)

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 498 frames (4h 9m)

Processing:

Siril 1.2.3:

Crop to 5000x3600px
BQ Octantis' technique of white balance, background subtraction, and histogram conditioning
StarNet:
- star desaturation
- separation into stars and background
- background: modified arcsinh and generalized hyperbolic stretches, background extraction, GraXpert denoise, GIMP levels (to darken the background a bit)
- stars: synthetic blue (B=2*G-R), modified arcsinh stretch, saturation
Single star RGB alignment on combined image

RawTherapee 5.9:

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

GIMP 2.10:

Luminance curve (just a touch)
Saturation