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M51 Aug 26, better blue, better processing

M51, Pinwheel Galaxy, project continuing. More blue collected to reduce noise in that channel, and each channel reprocessed to reduce sky glow gradient.

M51
Exposure
Luminance: 1.5 hours
Red: 65 min
Green: 90 min
Blue: 81 min
18 × 5-min unbinned
13 × 5-min binned 2 × 2
30 × 3-min binned 2 × 2
27 × 3-min binned 2 × 2
 
Camera
QSI583WSG
3348 x 2574 pixels of 5.4 µm
 
Temperature
Ambient 15° C
Chip -10° C
 
Telescope
AT8RC
1625mm f/l, f/8
 
Mount
Losmandy G11
 
Guiding
Lodestar
 
Processing
CCDStack
GradientXterminator
Median combine
 
© 2026 R.McDonald