The Clouds of Orion

The Clouds of Orion – a 2 panel mosaic in HaGB.

My first ever true color (ish) image! The 2020-21 winter in Europe hasn’t been great for astrophotography. All of my clear nights went into this project, and yet it took me 4 months to get (only) 22 hours of data.

Equipment

  • Samyang 135mm f/2
  • QHY163M
  • Baader narrowband filters
  • Antlia LRGB filters
  • Sky-Watcher HEQ5 Pro
  • QHY5L-II-C and QHY 30mm guidescope

Acquisition (Total : 22.6h)

  • Location : Backyard, bortle 5
  • Ha : 16.8 hours
  • G : 2.8 hours
  • B : 3 hours

Processing (PixInsight)

Individual channel processing

  • Gradient removal (DBE)
  • Background levels equalization (dnaLinearFit)
  • GradientMergeMosaic
  • Noise reduction (TGV and MMT)
  • HDRComposition (for Ha only, 30x10s stack)
  • HistogramTransformation
  • HDRMultiscaleTransformation

Luminance processing

  • Create a synthetic luminance L from G and B
    • ImageIntegration : noise evaluation, MAD estimator, no rejection
  • Merge Ha and L into a dynamic super luminance
  • StarNet++
  • Sharpening (MMT)
  • LocalHistogramEqualization
    • Two passes : kernel radius of 50 and 512
  • Adding the stars back (PixelMath)
  • Star reduction (tutorial)

LRGB processing

  • Final LRGB adjustments (52 in total)
    • Curves, selective saturation, MMT, DBE using various masks

Taken in November 2020 – March 2021

Leave a Reply

Your email address will not be published. Required fields are marked *