NGC 2158 - open cluster in Gemini

See a slightly better image here, with a bit more integration and (maybe) better processing

Acquisition:

Bortle 7 skies
Nikon D5600 camera
Orion Apex 102mm telescope, 1300mm focal length
iOptron CEM26 mount
30s x 200 frames
f/12.7
ISO 400

Processing:

SiriL:

Background extraction
Photometric color calibration
Generalized hyperbolic transformation

RawTherapee:

Contrast
Luminance and chrominance noise reduction
Median filter

GIMP:

Luminance curve
Noise reduction
Saturation
Black point