1 stack of 14 180s images, Canon 800D at ISO 800, Canon 50mm f1.8 lens at f4, iOptron Skyguider Pro tracker. 50 darks, 120 biases. Processed in PixInsight as below

***** Integration

lightvortexastronomy tutorial (https://www.lightvortexastronomy.com/tutorial-pre-processing-calibrating-and-stacking-images-in-pixinsight.html)

* CC defect list + master dark (sigma = 8)

15*(1-(FWHM-FWHMMin)/(FWHMMax-FWHMMin))

+ 35*(1-(Eccentricity-EccentricityMin)/(EccentricityMax-EccentricityMin))

+ 20*(SNRWeight-SNRWeightMin)/(SNRWeightMax-SNRWeightMin)

+ 30

img 7198 ref

* winsorized sigma clipping integration

* drizzle integration, gaussian kernel

*****Linear processing

*** Initial

* Crop

* DBE tolerance 2

* Crop some more, square framing

*** Luminosity fix for dust spot:

* Mask generation:

x_center=1426,

y_center=1022,

radius=100,

black_radius=65

iif(

inellipse(x_center,y_center, radius, radius),

iif(

inellipse(x_center,y_center, black_radius, black_radius),

0,

((rdist(x_center, y_center)- black_radius) / (radius-black_radius))

),

1

)

* With it on, histogram modify the image to brighten it and green it until the center of the dust spot is similar to existing background

* Clonestamp a bit of the ring halo

*** Color calibration

* Photometric CC using background near the Hyades with 0.005 limit, Pleiades as target, pixel size 2

* another background neutralization, this time a bit looser

* SNCR 0.8 green, preserve lightness

*** Denoise

Using https://jonrista.com/the-astrophotographers-guide/pixinsights/effective-noise-reduction-part-2/ as implemented by EZSuite.

* TGV edge protection 7e-5, default MMT

*** Secondary color fix

* PCC, same settings as before

* SNCR 0.8 green, preserve lightness

***** Nonlinear

*** Initial stretch and denoising

* masked stretch, default settings

* ACDNR with mask, as per https://jonrista.com/the-astrophotographers-guide/pixinsights/effective-noise-reduction-part-3/ (extract luminance, histo stretch with mid to 50%, blur 4 layers of a trous apply inverted) apply with lightness 0.5 amount, chrominance amount 1 structure size *

* extract luminance, histo stretch for mids to 50%, apply on image. Then, histogram stretch the image (shadows 0.08 mids 0.2

* EZDenoise, TGV 8e-3. default MMT

**** Starnet processing

** Initial

* split into starless + stars, clonestamp out artefact of dust clouds

*** Starless

** Denoise

* Create range mask from luminosity, lower limit 0.18, fuzziness 0.5

* With inverted range mask on, MMT biases layers 4-6 -0.05 -0.075 -0.1

** Colors

* with range mask on non-inverted, boost saturation and RGB slightly

** LHE

* apply range mask inverted

* kernel 512 contrast 1.5, 0.8 LHE + 0.2 original

* kernel 256 contrast 1.5, 0.67 LHE + 0.33 original

* kernel 128 contrast 1.5, 0.33 LHE + 0.67 original

** Background color fix

* with range mask inverted, curves boost saturation, and modify hue a bit to dial down the blueness of the non-dust sky

** Dust darkness enhance

* Range mask creation: give luminance high-contrast s-curve, range select the darkest bits with good feathering, then s-curve some more

* With that on, curves lower RGB-K

*** Stars

* star saturation increase

* star reduction

* second brightness and sat boost with curves

**** Sum back up, downsample 4x