The Whirlpool Galaxy (M51)

Equipment:
OTA: Celestron C9.25" w/ 0.63x Reducer (1480mm fl at f/6.3)
Mount: ZWO AM5N
Imaging camera: ZWO ASI1600MM-Cool
Guiding camera: ZWO ASI120MM-Mini OAG
Autofocuser: ZWO EAF

Software:
ASIAIR
PixInsight

Acquisition:
Location: Atoka, OK (Bortle 3)
Dates: 3/21/26
Gain: 76 Offset: 15
Camera temp: -10C
L: 34×300" ZWO 1.25in
R: 16×300" ZWO 1.25in
G: 16×300" ZWO 1.25in
B: 15×300" ZWO 1.25in
Total integration time: 6hr 45min
64x darks per calibration
30x flats per calibration
200x bias per calibration

Preprocessing:

WBPP script to generate calibrated images
StarAlignment
ImageIntegration
DynamicCrop each master

Luminance Processing:

DynamicBackgroundExtraction
BlurXTerminator
NoiseXTerminator
MultiscaleAdaptiveStretch
StarXTerminator
MultiscaleLinearTransform
Added stars back in using Pixelmath screen blend formula

Created RGB image with ChannelCombination

RGB Processing:

DynamicBackgroundExtraction
SpectrophotometricColorCalibration
BlurXTerminator
NoiseXTerminator
MultiscaleAdaptiveStretch

Combined RGB with Luminance using LRGBCombination

LRGB Processing:

SCNR Green
CurvesTransformations for color balance and saturation

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