It’s just a big ball of stars. I decided to try out a broadband target while waiting for some others to come into my view. Thanks to my wonderful horizons and the fact that this this is at dec +30 I only had a half hour window per night to shoot it. Still pleased with the results, especially with my light pollution. Captured over 4 nights from December 14-19, 2023 from a Bortle 9 zone.
DrizzleIntegration (2x, Var β=1.5) per panel per channel
Narrowband Linear:
DynamicBackground Extraction
duplicated each image and removed stars via StarXterminator. Ran DBE with a shitload of points to generate background model. model subtracted from original pic using the following PixelMath (math courtesy of /u/jimmythechicken1)
$T * med(model) / model
BlurXterminator for star correction
ArcsinhStretch + HistogramTransformation to bring nonlinear
RGB linear
DynamicBackground extraction as above
ChannelCombination to combine R G and B stacks into color image
SpectroPhotometricColorCalibration
BlurXterminator star correction
HSV Repair
ArcsinhStretch + HT to bring nonlinear
Nonlinear:
LRGBCombination with stretched RGB pic and stretched L pic as luminance
shitloads of CurveTransformations to adjust hue, lightness, saturation, etc. (some with lum masks)
It’s just a big ball of stars. I decided to try out a broadband target while waiting for some others to come into my view. Thanks to my wonderful horizons and the fact that this this is at dec +30 I only had a half hour window per night to shoot it. Still pleased with the results, especially with my light pollution. Captured over 4 nights from December 14-19, 2023 from a Bortle 9 zone.
Places where I host my other images:
Flickr | Instagram
Equipment:
TPO 6" F/4 Imaging Newtonian
Orion Sirius EQ-G
ZWO ASI1600MM-Pro
Skywatcher Quattro Coma Corrector
ZWO EFW 8x1.25"/31mm
Astronomik LRGB+CLS Filters- 31mm
Astrodon 31mm Ha 5nm, Oiii 3nm, Sii 5nm
Agena 50mm Deluxe Straight-Through Guide Scope
ZWO ASI-120mc for guiding
Moonlite Autofocuser
Acquisition: 2 hours 32 minutes (Camera at unity gain, -15°C)
Lum - 77x60"
Red - 27x60"
Green - 24x60"
Blue - 24x60"
Darks- 30
Flats- 30 per filter
Capture Software:
PixInsight processing:
Preprocessing
BatchPreProcessing
StarAlignment
Blink
ImageIntegration per channel per panel
DrizzleIntegration (2x, Var β=1.5) per panel per channel
Narrowband Linear:
BlurXterminator for star correction
ArcsinhStretch + HistogramTransformation to bring nonlinear
RGB linear
DynamicBackground extraction as above
ChannelCombination to combine R G and B stacks into color image
SpectroPhotometricColorCalibration
BlurXterminator star correction
HSV Repair
ArcsinhStretch + HT to bring nonlinear
Nonlinear:
LRGBCombination with stretched RGB pic and stretched L pic as luminance
shitloads of CurveTransformations to adjust hue, lightness, saturation, etc. (some with lum masks)
DeepSNR
Slight SCNR Green
More Curves
Resample to 70%
DynamicCrop again
Annotation