Cassiopeia on the Heart and Soul Nebula

Cassiopeia on the Heart and Soul Nebula

Cassiopeia on the Heart and Soul Nebula.

Full Resolution (30.0 MB)

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Equipment:

  • Celestron CGEM Mount

  • Voigtlander Ultron 40mm f2 at f5.6

  • asi071mc PRO at -15 C

  • Astronomiks L3 UV/IR filter

  • Manually Focused in NINA with the assistance of the Aberration Inspector and looping exposures.

Acquisition:

  • 153x6m Exposures
  • Total time: 15:18
  • Nights Imaged: 4
  • Started: 2022-10-17
  • Latest: 2022-10-20
Date L3
2022-10-17 2:48
2022-10-18 3:24
2022-10-19 5:36
2022-10-20 3:30
Totals 15:18

Session sequenced using Nighttime Imaging in Astronomy: N.I.N.A

All pre-processing and post-processing was done in PixInsight.

The resulting image is a combination of the following steps:

  • Inspected all subs for bad images with Blink, discarding subs containing clouds

  • Calibrated all subs with a master flat and master dark

  • Used subframe selector to weight all images using PSF Signal Weight

  • Selected the best sub from subframe selector and blink to use as a reference frame for aligning and integration

  • Calibrated (Darks, Flats, Dark Flats), Weighted and Aligned the best subs, tossing those with high clouds

  • Stacked the best 30 subs from the hightest altitude where minimum gradients existed and used as a Local Normalization reference

  • Applied local normalization to all 153x6m subs, then stacked using ESD and Large Scale Pixel Rejection

  • Drizzled 2x using CFA Drizzle

  • Performed a starless DBE to model the background, subtracting it from the full image

  • Generalized Hyberbolic Stretch:

    • Bring the black point in without clipping

    • Stretch in RGB mode using local intensity of 5 and stretch of 4

    • Stretch in Color mode using local intensity of -1 and stretch of 2.5

    • Stretch in Saturation mode using local intensity of -2 and stretch of 2.6

  • Created a contours based star mask then used erosion of morphological transform to reduce the impact of the stars

  • Ran deconvolution on the star cores

  • Additional GHS contrast based stretches in RGB and linear to bring the black point in further

  • Additional round of morphological transformation in selection selection to further reduce the impact of the stars

  • Increase contrast in medium and large scale features using Multiscale Median transformation, adjusting the Bias on wavelet layers 6-12 with a star mask in place

  • Chrominance Noise reduction using ACDNR on the dark regions

  • An ICC Profile was applied to enable Black Point Compensation



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