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Contains:  NGC 6995, Veil nebula, Network nebula, NGC 6992, IC 1340
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The Eastern Veil and Pickering's Triangle (NGC6992) imaged in HOO, 


            Andrew Klinger
The Eastern Veil and Pickering's Triangle (NGC6992) imaged in HOO

The Eastern Veil and Pickering's Triangle (NGC6992) imaged in HOO

Technical card

Imaging telescope or lens:William Optics GT-81

Imaging camera:ZWO ASI1600MM-Cool

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

Software:Cartes du CielPHD2EQMODPixInsightSequence Generator Pro

Filters:Astrodon OIII 3nmHa 5nm


Resolution: 3662x2743

Dates:June 27, 2018Aug. 7, 2018

Ha 5nm: 104x300" (gain: 200.00) -10C bin 1x1
Astrodon OIII 3nm: 17x300" (gain: 200.00) -10C bin 1x1

Integration: 10.1 hours

Darks: ~64

Flats: ~30

Bias: ~200

Avg. Moon age: 19.58 days

Avg. Moon phase: 60.38%

Bortle Dark-Sky Scale: 5.00 job: 2248389

RA center: 313.109 degrees

DEC center: 31.303 degrees

Pixel scale: 2.523 arcsec/pixel

Orientation: 11.656 degrees

Field radius: 1.603 degrees

Locations: Backyard, Flower Mound, Texas, United States

Data source: Backyard


OTA: William Optics GT81 w/0.8x reducer (382mm fl at f/4.7)
Mount: Orion Sirius EQ-G (HEQ-5)
Guidescope: Orion 50mm guidescope
Guiding camera: Orion StarShoot Autoguider
Imaging camera: ZWO ASI1600MM-Cool

DeepSkyDad Autofocuser
QHYCCD PoleMaster


Location: Flower Mound, TX for Ha(Bortle 7), Ft. Griffin State Historic Park for Oiii(Bortle 3)
Dates: 6/27/18, 6/28/18, 8/7/18
Gain: 200 Offset: 50
Camera temp: -10C
Ha: 104x300" Astrodon 5nm
Oiii: 17x300" Astrodon 3nm
Total integration time: 10hr 5min
64x darks per calibration (master from library)
30x flats per calibration
200x bias per calibration (master from library)

Batch PreProcessing script to generate calibrated images
DynamicCrop each master
DBE each master

Luminance Processing:
Created a synthetic luminance using the linear masters 60%Ha and 40%Oiii
TGV & MMT noise reduction (via Jon Rista's method)
HistogramTransformation x2
Duplicated the image to create a starless version, using a starmask and several iterations of MMT and MT. Then pushed the faint nebulosity in the starless version using PixelMath expression: "1-(1-$T)*(1-$T)"
Combined the starless version with the image using PixelMath expression "F=0.2; (1-(1-$T)*(1-s)*F)+($T*~F)" (s=starless photo).
HistogramTransformation to move black point in
MultiscaleLinearTransform for sharpening
CurvesTransformation for contrast

Preparing separate Ha and Oiii linear masters for tonmapping (applied to each master individually):
TGV & MMT noise reduction (via Jon Rista's method)
Removed stars via a StarMask and a few iterations of MMT and MT
Further removed background artifacts with an unmasked MMT
HistogramTransformation to bring to non-linear

Combined prepared Ha and Oiii masters with this PixelMath formula:
R: iif(ha>.15,ha,(ha*.8)+(oiii*.2))
G: iif(ha>0.5,1-(1-oiii)*(1-(ha-0.5)),oiii*(ha+0.5))
B: iif(oiii>.1,oiii,(ha*.3)+(oiii*.2))

Tonemap Processing:
HistogramTransformation with a RangeMask to push the fainter areas up a bit
HDRMT the brighter areas
A few CurvesTransformations using ColorMasks to alter the colors a bit

Combined Tonemap with Luminance using LRGBCombination
SCNR>Invert>SCNR with a StarMask to remove magenta stars
MT for slight star reduction
MMT for slight noise reduction
Resampled to 40% for web posting



Andrew Klinger
License: None (All rights reserved)

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The Eastern Veil and Pickering's Triangle (NGC6992) imaged in HOO, 


            Andrew Klinger