The Squid, the Elephant and the Bat

The Squid, the Elephant and the Bat – a zoo in the sky.

The Giant Squid Nebula (blue, top left) is a planetary nebula that was discovered in 2011 by the french amateur astrophotographer Nicolas Outters. It’s big, very faint and exclusively OIII. Seriously, it’s very very faint.

This image also includes the Flying Bat nebula (red, top left) and the Elephant’s trunk nebula (bottom right).


  • Samyang 135mm f/2
  • QHY163M
  • Baader narrowband filters
  • Sky-Watcher Star Adventurer
  • QHY5L-II-C and QHY 30mm guidescope

Acquisition (Total : 60.4h)

  • Location : Backyard, bortle 5
  • Ha : 270x300s (22.5h)
  • OIII : 164x600s (27.3h)
  • SII : 127x300s (10.6h)
  • Calibration : darks, flats

Processing (PixInsight)

Linear (on Ha, OIII, and SII)

  • DynamicCrop

  • DynamicBackgroundExtraction

  • Deconvolution (Ha only) (tutorial)

  • Noise reduction (TGV and MMT)

  • HistogramTransformation

  • OIII halos/reflections removal in Photoshop

Color combination (tutorial)

  • R  : OIII*SII + ~OIII*(.1*SII+.9*Ha)
  • G : Ha*(0.7*Ha+0.3*OIII) + ~Ha*OIII
  • B  : OIII*OIII + ~OIII*(.3*SII+.7*OIII)

Non-linear (creation of a luminance based on Ha and OIII)

  • Starnet++

  • Additional noise reduction and stretching on OIII

  • L : max(OIII, Ha)

  • Elliptical shaped mask (made with the GAME script) around the squid to blend L with Ha

  • Sharpening (MMT)

  • HDRMultiscaleTransform

  • LocalHistogramEqualization

  • CurvesTransformation

  • Adding the stars back (PixelMath)

Final adjustments

  • CurvesTransformation
  • Starnet++
  • DynamicBackgroundExtraction
  • BackgroundNeutralization
  • Adding the stars back (PixelMath)
  • Chrominance noise reduction (MMT)
  • Fixing the stars color (SCNR, ColorSaturation and Lightroom)
  • Star reduction (tutorial)
  • CurvesTransformation

Taken in April – May 2020

4 Replies to “The Squid, the Elephant and the Bat”

  1. Love this photo! Hoping to be able to capture something remotely similar to this once my skies clear in Sep… Is that 135mm/f2 worth it for widefield? I have a couple of canon and sony lenses but nothing f2. Thanks.

  2. PS: I also have a QHY 163M.. can you share how you connect yours to the 135mm f/2? I know the lens adapter is needed but any spacers for the back focus, etc? Thanks.

    1. Hi! I used the Blade-C adapter from CyclopsOptics coupled with the 020063 QHY adapter and didn’t need any additional spacers. I believe you need the UltraSlim version of the CFW for this to work though.

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