| categories:Astrophotography

Cygnus Wall - North America Nebula

First light of a new setup! Getting back into the astrophoto game after being away for a few years. Still tweaking/tuning the mechanical aspects: coma corrector is at the incorrect spacing so there is some noticeable coma in all corners, and polar alignment could use some work (can definitely see some elongated stars). Also pretty sure my collimation is off since I can see double (offset) diffraction spikes.

Colors got a bit wonky as I processed, but since the raw data itself is suspect I didn't spend too long fiddling with processing. Will revisit once I get all the mechanical bits tuned up :)


  • 15x200s, 20x300s Ha
  • 20x300s Sii
  • 25x300s Oiii
  • 20x darks, no bias or flats

Total integration ~6 hours, although some of the subs were weighted quite lowly due to bad FWHM or thin cloud cover. Hodgepodge of exposures are from different nights as I grabbed a few hours here and there. Seeing was pretty garbage for most of it, and between poor alignment + bad seeing I was averaging ~1-3” RMS error


  • ASI1600mm Pro
  • ZWO narrowband filter set
  • Orion 8” f3/9 astrograph
  • AP1100 GTO mount
  • Moonlight focuser
  • ASI120mini and generic 60mm guidescope


  • Bortle 4-4.5 ish
  • Minimal cloud cover, “below average” seeing, “below average” to “average” transparency

Pixinsight Processing:

  1. Calibrate, register, SubframeSelector to weight, integrate, drizzle
  2. DBE
  3. TGVDenoise
  4. LinearFit to normalize three channels
  5. ChannelCombination in SHO pallete
  6. PixelMath to de-magenta stars
  7. BackgroundNeutralization
  8. Curve tweak
  9. SCDNR to remove most of green/teal
  10. HDRMultiscaleTransform, LocalHistogramEqualization with varying masks
  11. Bunch of faffing around with saturation, curves, histogram stretches
  12. Finished with DarkStructureEnhance
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