Celestial hemisphere:  Southern  ·  Constellation: Sagittarius (Sgr)  ·  Contains:  Checkmark Nebula  ·  IC 4706  ·  IC 4707  ·  Lobster Nebula  ·  M 17  ·  NGC 6596  ·  NGC 6618  ·  Swan Nebula  ·  omega Nebula
M 17 - The Omega Nebula, robo9981
M 17 - The Omega Nebula
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M 17 - The Omega Nebula

M 17 - The Omega Nebula, robo9981
M 17 - The Omega Nebula
Powered byPixInsight

M 17 - The Omega Nebula

Equipment

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Acquisition details

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Description

M 17 - Omega Nebula

Managed to sneak in a little bit of time on M 17 between the endless stream of clouds and rain.  This monsoon season has been rough.
I'm very happy with how this turned out given the relatively short integration time and my skies.  This was all shot from my backyard
in B7 skies, but facing towards the south where my skies are a bit better.  I want to get an SQM to see what my actual sky brightness
levels are.

L: 177x60s = 2.95 hours
R: 40x60s = 0.66 hours
G: 41x60s = 0.68 hours
B: 40x60s = 0.66 hours
Total: 4.96 hours

Equipment:
  • GSO 6" f/4 Newtonian
  • ZWO ASI1600-MM Pro
  • ZWO 31mm LRGB filters
  • iOptron CEM40
  • NINA for acquisition & PixInsight for processing


Preprocessing:
  1. WBPP for calibration
  2. SubframeSelector
  3. ImageRegistration
  4. Integration
  5. DrizzleIntegration (vark1.5, scale 2)


L Processing:
  1. DynamicCrop
  2. DBE
  3. Starless Deconvolution following https://thecoldestnights.com/2020/06/pixinsight-deconvolution-on-starless-images/
  4. IntegerResample back to original resolution
  5. TGVDenoise (with a low contrast mask, using EZDenoise)
  6. Stretched separate copies with HistogramTransformation & MaskedStretch
  7. Blended the two with PixelMath (straight average)

RGB Processing[b]:[/b]
  1. DynamicCrop
  2. DBE
  3. BackgroundNeturalization
  4. PhotometricColorCalibration
  5. 2x Arcsinh Stretch
  6. HistogramTransformation for last stretch
  7. LRGBCombination w/ L channel (Chrominance Noise Reduction enabled)
  8. CurvesTransformation for saturation and contrast
  9. MMT to reduce some additional chrominance noise
  10. BackgroundNeutralization to bring colors back in line
  11. LHE
  12. MorphologicalTransformation to reduce stars.  Noise added to contours in L channel and recombined
  13. MMT for some slight mottle reduction
  14. CurveTransformation for days to do final tweaks.
  15. Very slight UnsharpMask for additional sharpening

Comments

Sky plot

Sky plot

Histogram

M 17 - The Omega Nebula, robo9981