Equipment:

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

Software:

SGP

PHD2

CdC

PixInsight

Acquisition:

Location: Flower Mound, TX for Ha(Bortle 7), Atoka, OK for RGB(Bortle 3)

Dates: 10/1/17, 11/18/17

Gain: 200 Offset: 50 for Ha

Gain: 76 Offset: 15 for RGB

Camera temp: -20C

Ha: 101x180" Astrodon 5nm

R: 13x180"

G: 14x180"

B: 12x180"

Total integration time: 7hrs

64x darks per calibration

30x flats per calibration

200x bias per calibration

Preprocessing:

Batch PreProcessing script to generate calibrated images

StarAlignment to register all frames to the reference

LocalNormalization of all registered frames (per channel)

ImageIntegration of each channel

DrizzleIntegration of each channel

DynamicCrop each master

DBE each master

Using PixelMath, blended linear Ha with linear masters (50% into R, 10% into B, 5% into G)

Ha Processing:

Deconvolution

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).

HDRMulitiscaleTransform

LocalHistogramEqualization with inverted starmask

UnsharpMask slight sharpening

MorphologicalTransformation slight star reduction

CurvesTransformation slightly increase brightness

DarkStructureEnhance Script

RGB Processing:

Linear Fit to Red channel

ChannelCombination to create RGB

PhotometricColorCalibration

SCNR green

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

HistogramTransformation x2

SCNR green

CurvesTransformation for saturation

Combined Ha and RGB using the script HaRVB-AIP

SCNR green (darn green keeps coming back)

PixelMath with a StarMask to add the original RGB stars back into the image (they looked weird beforehand)

Resampled to 50% for web posting