Omega Centauri is the largest globular cluster in the sky and contains about 10 million stars, but it’s generally considered a southern hemisphere target since it’s at -47 declination. It was right at the meridian for me while waiting for it to get completely dark out, so I tried shooting it at just 9 degrees up. Had to do short exposures without guiding, because even the dim flashlights of the other campers with me would overwhelm my guide camera. Captured on June 7th, 2024 from a Bortle 3 zone (Deerlick Astronomy Village)
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
Luminance:
BlurXTerminator (correct only mode)
ArcsinhStretch + histogramtransformation to bring nonlinear
RGB:
ChannelCombinaiton to combine monochrome R, G, B stacks into color image
BlurXTerminator (correct only mode)
SpectroPhotometricColorCalibration
HSV Repair
MMT for large scale chrominance noise reduction
ArcsinhStretch + histogramtransformation to bring nonlinear
Nonlinear:
LRGBCombination with stretched L as luminance
Several CurveTransformations to adjust lightness, contrast, colors, saturation, etc.
Omega Centauri is the largest globular cluster in the sky and contains about 10 million stars, but it’s generally considered a southern hemisphere target since it’s at -47 declination. It was right at the meridian for me while waiting for it to get completely dark out, so I tried shooting it at just 9 degrees up. Had to do short exposures without guiding, because even the dim flashlights of the other campers with me would overwhelm my guide camera. Captured on June 7th, 2024 from a Bortle 3 zone (Deerlick Astronomy Village)
Places where I host my other images:
Instagram | Flickr
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: 12 minutes (Camera at half Unity Gain, -15°C)
Lum - 20x10"
Red - 11x15"
Green - 13x15"
Blue - 12x15"
Flats- 30 per filter
Capture Software:
PixInsight Processing:
BatchPreProcessing
StarAlignment
Blink
ImageIntegration
DrizzleIntegration (2x, Var β=1.5)
DynamicCrop
DynamicBackgroundExtraction
Luminance:
BlurXTerminator (correct only mode)
ArcsinhStretch + histogramtransformation to bring nonlinear
RGB:
ChannelCombinaiton to combine monochrome R, G, B stacks into color image
BlurXTerminator (correct only mode)
SpectroPhotometricColorCalibration
HSV Repair
MMT for large scale chrominance noise reduction
ArcsinhStretch + histogramtransformation to bring nonlinear
Nonlinear:
LRGBCombination with stretched L as luminance
Several CurveTransformations to adjust lightness, contrast, colors, saturation, etc.
DeepSNR Noise reduction
HistogramTransformations
More curves
Resample to 70%
Annotation