Veil nebula complex

Tags: 2019-07-07 ngc6995 ngc6960 widefield nebula dso astrophotography ccd narrowband bicolor
Acquisition date(s):
2019-07-07, 2018-08-07, 2018-08-08, 2018-08-09 2018-08-17, 2018-08-18, 2018-08-27
Description
Fire in the sky. Eastern and Western Veil nebulas with Pickerings triangle in the middle. Witch's broom. Finger of God. Network Nebula. So many names for this structure or parts of it. And this structure is a supernova remnant, which exploded approximately 8000 years ago. In our sky it is huge, as big as Andromeda galaxy. Unfortunately, visually, it is a challenging object and not for small apertures. But, it is easily picked up by a camera, even a simple unmodified DSLR. I have imaged part of this nebula 4 years ago, and it still came out quite great, but processing needs rework now.

Equipment/Acquisition Details:

Imaging Scope: Samyang 135mm F2 (shot at F2)

Imaging Camera: Starlight Xpress Trius-SX694 Mono CCD

Filter Wheel: Gerd Neumann filter drawer

Filters: 1.25" mounted Astrodon Ha 3nm and Astrodon OIII 3nm

Guide Camera: Lodestar X2 using Skywatcher 50mm viewfinder as guidescope

Mount: SkyWatcher NEQ6 with wedge upgrade, hypertuned, Star Adventurer (some subs were on one mount, others on another)

Accessories/Software: QHY Polemaster, EQMOD, PHD2, Sequence Generator Pro, PixInsight

Integration Details: 112x300ss Ha (1x1bin), 94x300s OIII (1x1bin) TOTAL: 17.2 hours.

Dates: 2018-08-07, 2018-08-08, 2018-08-09 2018-08-17, 2018-08-18, 2018-08-27,

Darks: 30

Flats: 30

Bias: 200

Processing details:

Pre-processing

SFS process to calculate weigh keyword
2x Drizzle integration
Crop

Ha

DBE
Deconvolution using PSF, and 0 global dark deringing, then adding non deconvolved stars back using star mask
TGV denoise using low contrast and strong mask
MMT using 8 layers without adaptive setting and strong mask
HistogramTransformation- stretch to taste
MLT to increase sharpnes using lum mask
Adam Block's approach towards removing stars- creating star ring mask using bloatedStarMask-starmask, then making a starless image, and replacing the ring space with starless image pixels.

OIII

DBE
Deconvolution using PSF, and 0 global dark deringing, then adding non deconvolved stars back using star mask
TGV denoise using low contrast and strong mask
MMT using 8 layers without adaptive setting and strong mask
HistogramTransformation- stretch to taste
MLT to increase sharpnes using lum mask
Adam Block's approach towards removing stars- creating star ring mask using bloatedStarMask-starmask, then making a starless image, and replacing the ring space with starless image pixels.

Bicolor

Removed stars in OIII and Ha with StarNet++
PixelMath to combine

Red: iif(ha > .15, ha, (ha*.8)+(oiii*.2))
Green: iif(ha > 0.5, 1-(1-oiii)*(1-(ha-0.5)), oiii *(ha+0.5))
Blue: iif(oiii > .1, oiii, (ha*.3)+(oiii*.2))

SCNR
CurvesTransformation to increase contrast, saturation and color tweaks
MMT using 7 layers and adaptive setting
Create L using PixelMath formula iif(ha>oiii,ha,oiii)
LRGBCombination
BackgroundEnhance script so that the faint dust pops more
Invert->SCNR green->invert to reduce unwanted magenta in background
ColorSaturation for various bands
SCNR to reduce green slightly
ICCProfileTransformation assign sRGB profile
Resample to original size
Signature script