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Contains:  NGC 1999, M 43, NGC 1982, NGC 1977, NGC 1980, M 42, Great Nebula in Orion, NGC 1976, NGC 1975, NGC 1981, NGC 1973, The star 45Ori, The star ιOri, The star θ2Ori, The star θ1Ori, The star 42Ori
Getting plate-solving status, please wait...
M42 - Orion Nebula, 


            Andrew Klinger
M42 - Orion Nebula

M42 - Orion Nebula

Technical card

Imaging telescope or lens:William Optics GT-81

Imaging camera:Canon EOS 600D / Rebel T3i

Mount:Orion Sirius EQ-G (HEQ5)

Guiding telescope or lens:Orion 50 mm Guide Scope

Guiding camera:Orion Star Shoot Auto Guider

Focal reducer:William Optics Flat 6A


Resolution: 4824x3257

Dates:Nov. 30, 2016

Frames: 32x480" ISO800

Integration: 4.3 hours

Darks: ~20

Flats: ~30

Bias: ~200

Avg. Moon age: 0.88 days

Avg. Moon phase: 0.88%

Bortle Dark-Sky Scale: 3.00 job: 2052939

RA center: 83.804 degrees

DEC center: -5.415 degrees

Pixel scale: 2.288 arcsec/pixel

Orientation: 89.471 degrees

Field radius: 1.850 degrees

Locations: Atoka dark site, Atoka, Oklahoma, United States


Data acquired 11-28-16 and 11-30-16 in Atoka, OK
Scope: William Optics GT81 w/ 0.8x reducer (382mm focal length at f/4.7)
Mount: Orion Sirius EQ-G
Guidescope: Orion 50mm guidescope
Guiding camera: StarShoot Autoguider
Imaging camera: Canon t3i (unmodified)

32x480" lights
Core data:
(4hr 44min total integration time)
20x darks per subset
30x flats per subset
200x bias

Processing Details:

Preparing each subset for combination:

Combined each subset using HDRComposition

BackgroundNeutralization->Deconvolution->MultiscaleLinearTransform for NR->HistogramTransformation->HDRMultiscaleTransform

(almost all of the processing from here on uses masks crafted with PixInsight and Photoshop to edit specific areas of the image)

Made a copy of image to create a semi-starless version:
Removed stars using several iterations of MultiscaleMediumTransform and MorphologicalTransformation->Pushed nebulosity with PixelMath expression "1-(1-$T)*(1-$T)"

Combined starless version with image using PixelMath expression "F=0.4; (1-(1-$T)*(1-s)*F)+($T*~F)" followed by the same function but with a value of F=0.2. (s = starless photo).

HistogramTransformation->CurvesTransformation to selectively push dusty regions->DarkStructureEnhance->HistogramTransformation->SCNR green->ColorSaturation tool on entire image->ColorSaturation tool to target specific nebulosity colors->Resampled to 50% for web posting



Andrew Klinger
License: None (All rights reserved)

Sky plot

Sky plot


M42 - Orion Nebula, 


            Andrew Klinger