This false-color narrowband image shows the Hydrogen and Sulfur as warmer tones and Oxygen as blue.

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, Atoka, OK (Bortle 3) for SII and OIII

Dates: 1/6/20, 1/7/20, 2/26/20, 2/27/20, 2/28/20

Gain: 200 Offset: 50

Camera temp: -20C

Ha: 168x300" Astrodon 5nm 1.25"

SII: 51x600" Astrodon 3nm 1.25"

OIII: 48x600" Astrodon 3nmn 1.25"

Total integration time: 30hr 30min

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 the master Ha to use as the luminance

Deconvolution

ArcsinhStretch and HistogramTransformation to bring to non-linear

Created a duplicate starless version using StarNet++

Combined the starless version with the image using PixelMath expression "F=0.4; (1-(1-$T)*(1-s)*F)+($T*~F)". (s=starless photo)

LocalHistogramEqualization

MultiscaleLinearTransform for sharpening

CurvesTransformation

MorphologicalTransformation for star size reduction

UnsharpMask to harden up reduced stars

Preparing separate Sii, Ha, and Oiii linear masters for tonemapping (applied to each master individually):

TGV & MMT noise reduction (via Jon Rista's method)

ArcsinhStretch and HistogramTransformation to bring to non-linear

Removed stars via StarNet++

Removed small artifacts by removing the first 3 layers via MMT

LinearFit to Ha

Combined prepared Sii, Ha, and Oiii masters with ChannelCombination:

R: Sii

G: Ha

B: Oiii

Tonemap Processing:

HistogramTransformation to balance colors

CurvesTransformation

Invert>SCNR>Invert using a previously created magenta ColorMask to remove magentas

CurvesTransformation using ColorMasks

Combined Tonemap with Luminance using LRGBCombination:

CurvesTransformation for slight contrast

Resampled to 30% for web posting