Imaging telescopes or lenses: William Optics GT-81
Imaging cameras: ZWO ASI1600MM-Cool
Mounts: Orion Sirius EQ-G (HEQ5)
Guiding telescopes or lenses: Orion 50 mm Guide Scope
Guiding cameras: Orion Star Shoot Auto Guider
Focal reducers: William Optics Flat 6A
Software: Sequence Generator Pro · PHD2 · Cartes du Ciel · EQMOD · PixInsight
Filters: Astrodon SII 3nm · Astrodon OIII 3nm · Ha 5nm
Accessory: PoleMaster
Dates:July 19, 2020 , Aug. 9, 2020
Frames:
Ha 5nm: 337x300" (gain: 200.00) -10C bin 1x1
Astrodon OIII 3nm: 12x600" (gain: 200.00) -10C bin 1x1
Astrodon SII 3nm: 11x600" (gain: 200.00) -10C bin 1x1
Integration: 31.9 hours
Darks: ~64
Flats: ~30
Bias: ~200
Avg. Moon age: 24.22 days
Avg. Moon phase: 36.06%
Bortle Dark-Sky Scale: 2.00
Astrometry.net job: 3804334
RA center: 22h 43' 7"
DEC center: +58° 15' 10"
Pixel scale: 4.041 arcsec/pixel
Orientation: 1.407 degrees
Field radius: 1.571 degrees
Resolution: 2264x1646
Locations: Backyard, Flower Mound, Texas, United States
Data source: Backyard
NGC7380, an open star cluster, lies in the constellation Cepheus 8000 light years away. The surrounding interstellar gas is displayed in false-color here. The warmer tones represent Hydrogen-alpha and Sulfur-II emissions while blues represent Oxygen-III emissions.
Equipment:
OTA: William Optics GT81 w/0.8x reducer (382mm fl at f/4.7)
74mm aperture stop-down ring (brings scope to f/5.2)
Mount: Orion Sirius EQ-G (HEQ-5)
Guidescope: Orion 50mm guidescope
Guiding camera: Orion StarShoot Autoguider
Imaging camera: ZWO ASI1600MM-Cool
Accessories:
DeepSkyDad Autofocuser AF1
QHYCCD PoleMaster
Software:
SGP
PHD2
CdC
PixInsight
Acquisition:
Location:
Flower Mound, TX (Bortle 7) for Ha
Ft. Griffin State Historic Park, TX (Bortle 2) for Oiii and Sii
Dates: 7/19/20, 8/9/20, 8/10/20, 8/11/20, 8/12/20, 8/13/20,
Gain: 200 Offset: 50
Camera temp: -10C
Sii: 11x600" Astrodon 3nm 1.25"
Ha: 337x300" Astrodon 5nm 1.25"
Oiii: 12x600" Astrodon 3nm 1.25"
Total integration time: 31hr 55min
64x darks per calibration (master from library)
30x flats per calibration
200x bias per calibration (master from library)
Preprocessing:
Batch PreProcessing script to generate calibrated images
StarAlignment
ImageIntegration
DrizzleIntegration
DynamicCrop
DBE
Luminance Processing:
Duplicated master Ha to use as the Luminance
Duplicated the image again to later use for stars
Used PixelMath and StarNet to stretch, remove stars, and then return to linear
Deconvolution
ArcsinhStretch
HistogramTransformation
LocalHistogramEqualization
MultiscaleLinearTransform
TGVDenoise
CurvesTransformation
Used PixelMath to insert stars from the duplicated master
MorphologicalTransformation to reduce star sizes
UnsharpMask to slightly sharpen stars
MultiscaleMedianTransform to smooth blotchy noise
HistogramTransformation
MultiscaleLinearTransform
Preparing separate Sii, Ha, and Oiii linear masters for tonemapping (applied to each master individually):
Removed stars by stretching, running StarNet, and inverting the stretch to return to linear
TGV & MMT noise reduction (via Jon Rista's method)
HistogramTransformation to bring to non-linear
Combined prepared Sii, Ha, and Oiii masters with ChannelCombination:
R: Sii
G: Ha
B: Oiii
Tonemap Processing:
CurvesTransformation with ColorMasks to balance colors
Invert>SCNR>Invert using a mask to remove magenta from background sky
MultiscaleMedianTransform to reduce blotchy noise
TGVDenoise
CurvesTransformation for more color balance
Combined Tonemap with Luminance using LRGBCombination:
CurvesTransformation for slight contrast
Resampled to 25% for web posting
Comments