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

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

 

Accessories:

DeepSkyDad Autofocuser

QHYCCD PoleMaster

 

Software:

SGP

PHD2

CdC

PixInsight

 

Acquisition:

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)

 

Preprocessing:

Batch PreProcessing script to generate calibrated images

StarAlignment

LocalNormalization

ImageIntegration

DrizzleIntegration

DynamicCrop each master

DBE each master

 

Luminance Processing:

Created a synthetic luminance using the linear masters 60%Ha and 40%Oiii

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).

HistogramTransformation to move black point in

LocalHistogramEqualization

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

Done