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M33 - Triangulum Galaxy LHaRGB

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#1 BBC

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Posted 22 September 2019 - 06:13 PM

LHaRGB v1.1 CN.jpg

 

https://www.astrobin...v/0/?real=&mod=

 

Imaging telescope: Mallincam VRC-8
Imaging camera: Atik 383L+ mono
Mount: CEM60
Guiding telescope: Mallincam VRC-8
Guiding camera: Starlight Xpress Loadestar X2
Focal reducer: CCDT67

Filters:

  • Astrodon 36mm Tru-Balance E-Series Blue
  • Astrodon 36mm Tru-Balance E-Series Green
  • Astrodon 36mm Tru-Balance E-Series Red
  • Astrodon 36mm Tru-Balance E-Series Luminance
  • Astrodon H-Alpha 3nm

Accessories:

  • Atik EFW2 Filter Wheel
  • Atik OAG
  • Moonlite High res stepper motor and Mini-V2 controller

Software:

  • PixInsight PinInsight 1.8
  • Main Sequence Software Sequence Generator
  • PHD2

Dates:

  • Sept. 19, 2019
  • Sept. 20, 2019
  • Sept. 21, 2019
  • Sept. 22, 2019

Frames:

  • Astrodon 36mm Tru-Balance E-Series Blue: 18x600" -20C bin 1x1
  • Astrodon 36mm Tru-Balance E-Series Green: 18x600" -20C bin 1x1
  • Astrodon 36mm Tru-Balance E-Series Luminance: 36x300" -20C bin 1x1
  • Astrodon 36mm Tru-Balance E-Series Red: 18x600" -20C bin 1x1
  • Astrodon H-Alpha 3nm: 21x1200" -20C bin 1x1

Resolution: 2400x3100
Pixel scale: 1.085 arcsec/pixel
Integration: 19.0 hours
Avg. Moon age: 21.06 days
Avg. Moon phase: 61.15%
Bortle Dark-Sky Scale: 7.00
RA center: 23.464 degrees
DEC center: 30.657 degrees
Orientation: 89.960 degrees
Field radius: 0.591 degrees


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#2 Tom K

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Posted 22 September 2019 - 07:36 PM

Nicely done - I would be interested to learn from your PI workflow.


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#3 stargazer60

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Posted 22 September 2019 - 07:52 PM

Very nice, great detail and color separation.  Keep up the great work. waytogo.gif 


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#4 BBC

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Posted 22 September 2019 - 08:12 PM

Nicely done - I would be interested to learn from your PI workflow.

Thank you, Tom.  Here is my workflow ...

 

Preprocessing:

  • Calibration with Flats and Darks on L, R, G and B. Calibration of Ha with Darks only.
  • Cosmetic Correction on L, R, G, B and Ha
  • StarAlignment w/ Nearest Neighbor pixel interpolation on L (lowest FWHM Red image as reference)
  • StartAlignment w/ Auto pixel interpolation on R, G, B and Ha (lowest FWHM Red image as reference)
  • Individual ImageIntegration on L, R, G, B and Ha with Sigma low 3.3, Sigma high 2.2 and low and high large scale rejection enabled (default settings)

Luminance:

  • Several iterations of DBE with various points to beat down light pollution in Lum
  • Deconvolution
  • Minor noise reduction with MLT w/ layer and first layer disabled
  • ArcSinhStretch, HistogramTransformation
  • HDRMT on extracted preview of galaxy - 7 layers, lightness mask, Small scale 8 (3) scaling
  • Apply extracted preview back into Luminance w/ PixelMath formula
  • CurvesTransformation adjustment
  • Set black point with STF and apply using HistogramTransformation

RGB:

  • Several iteration of DBE with various points on R, G, and B
  • ChannelCombination with R, G and B
  • PhotometricColorCalibration
  • MLT w/ 1 layer and first layer disabled
  • SCNR
  • ArcsinhStretch, HistogramTransformation

Finish:

  • LRGBCombination L to RGB image w/ lightness and saturation transfer functions lowered from 0.5
  • ColorSaturation to adjust reds and blues
  • Noise reduction with mask protection high signal - MLT w/ 1 layer and first layer disabled
  • Noise reduction with mask protection low signal - TGVDenoise L*a*b mode and applying both Luminance and Chrominance
  • Set black point with STF and apply using HistogramTransformation
  • MaskedStretch Ha image
  • Extract Red channel from RGB
  • PixelMath to combine Red and Ha image w/ formula ((HA * R_bandwidth) - (R * HA_bandwidth)) / (R_bandwidth - HA_bandwidth) and setting bandwidth of HA _bandwidth as per filter (3nm in my case) and manipulating R_bandwidth until a desire image is achieved
  • Apply HaR combined image back into RGB image with Pixel Math - R formula: $T + ((CombImg - Med(CombImg)) * BoostFactor), G and B as $T, BoosFactor was 0.75
  • ColorSaturation adjustments with low signal masked
  • UnsharpMask with low signal masked
  • Created new RGB image with ChannelCombination
  • MaskedStretch to new RGB image
  • Apply star mask to original RGB image to expose larger, brighter stars - those blown out by ArcsinhStretch
  • Overlay stars of new RGB image with PixelMath
  • Used GAME script to isolate larger stars and create mask
  • Apply star mask to image and use MorphologicalTransformation to reduce stars, followed by slight desaturation w/ CurvesTransformation
  • HDMRT again to higher signal of galaxy w/ galaxy mask applied
  • Slight boost of blue channel again w/ galaxy mask applied using PixelMath
  • Final ColorSaturation adjustments
  • Final black point and midtones adjustment w/ HistogramTransformation

 

Hope this helps!!



#5 Tom K

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Posted 22 September 2019 - 08:44 PM

Wow - that is something else!   My PI skills definitely need a tune up!  




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