Caldwell 34 - Veil Nebula

Caldwell 34 - Veil Nebula

The Veil Nebula is a cloud of heated and ionized gas and dust in the constellation Cygnus. It constitutes the visible portions of the Cygnus Loop (radio source W78, or Sharpless 103), a large but relatively faint supernova remnant. The source supernova exploded circa 3,000 BC to 6,000 BC, and the remnants have since expanded to cover an area roughly 3 degrees in diameter (about 6 times the diameter, or 36 times the area, of the full Moon). The distance to the nebula is not precisely known, but Far Ultraviolet Spectroscopic Explorer (FUSE) data supports a distance of about 1,470 light-years. (Source: Wikipedia)

This is my first object captured with all three narrowband filters (Hα, OIII, SII).

Exposure data

Count Exposure Data Filter Nights
35x 300s Hydrogen-alpha Astronomik 6nm Hα 2018-06-26
33x 600s Oxygen-III Astronomik 6nm OIII 2018-07-27 / 2018-07-29
33x 600s Sulphur-II Astronomik 6nm SII 2018-06-30 / 2018-07-01

Total integration: 13 hours 55 minutes

Instrument and equipment

  • Canon EF 200mm f/2.8L at f/3.5
  • Skywatcher H-EQ5
  • Canon EOS 1300Da
  • Lacerta M-Gen Autoguider
  • Astronomik Hα, OIII, SII filters
  • TS-Optics 60mm Guide tube


  • Balcony observatory, Germany, BW
  • Bortle 4

Used software

  • APT + Stellarium for camera control
  • EQMod for telescope control
  • PixInsight for image processing
  • Photoshop for final touch

PixInsight processing workflow:

  • Calibration, Weighting (SFS), Integration
  • DrizzleIntegration (2x)
  • DBE for HA, OIII, SII masters
  • Ha+OIII LinearFit against SII
  • PixelMath for RGB (R=HA, G=SII0.8+OIII0.2, B=OIII0.8+SII0.2)
  • RGBWorkingSpace
  • ABE
  • BackgroundNeutralization
  • ColorCalibration
  • TGVDenoise
  • MMT
  • Deconvolution
  • ArcsinhStretch
  • HT + CT for color and contrast improvance
  • MT for star shrink
  • LHE for more contrast
  • UnsharpMask
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About Daniel Vogelbacher

Hi, I'm Daniel, a software developer, Linux administrator and landscape photographer.