Monthly Archives: February 2024

M42 The Orion Nebula and M101 the Pinwheel Galaxy: First Light with New Astrophotography Equipment

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Back at the end of November, I bought some new astrophotography tools/toys: 

  • ZWO 2” Electronic Filter Wheel
  • Antila LRGBSHO filters
  • ZWO ASI183MM-Pro-Mono camera
  • ZWO ASiair Plus

Of course, as the old astrophotography joke goes, buying new tools meant we had seemingly months of cloudy skies.

Happily, this time of year meant I got to have first light with one of my favorite Deep Space Objects: M42 the Orion Nebula.

I finally got an opportunity for first light with the new equipment December 29, 2023, but the filter wheel was jammed by one of the connecting tubes (I ordered a better one) so I didn’t get any good data.  

I got a second opportunity on December 30, 2023 but I had to resort to swapping in the filters by hand, which meant bringing the telescope back inside to change out filters and restarting ASiair every time.  The resulting images ended up rotated relative to one another in such a way that I couldn’t crop out all the sections that weren’t covered by all three filters.  This wasn’t surprising since I had to unscrew all the parts to swap out filters.  I also think I may have mislabeled which set of images was which color since the result came out an odd purple color.  Rotating the color assignments seemed to fix that.  The experience gave me a real appreciation for the filter wheel! 

Here is the processed image:

Camera geek info:

  • Williams Optics Zenith Star 73 III APO telescope
  • Williams Optics Flat 73A
  • Antila RGB filters
  • ZWO ASI183MM-Pro-Mono camera
  • ZWO ASiair Plus
  • iOptron CEM40
  • Friendswood, Texas Bortle 7-8 suburban skies

Frames:

  • December 30, 2023
    • RGB lights
      • 52 60 second Gain 50 R lights
      • 30 60 second Gain 50 G lights 
      • 54 60 second Gain 50 B lights 
    • 30 0.05 second Gain 50 RGB flats
    • 30 0.05 second Gain 50 flat darks
    • 30 60 second Gain 50 darks

Processing geek info:

  • PixInsight
  • BlurXterminator
  • NoiseXterminator
  • StarXTerminator
  • Generalized Hyperbolic Stretch

I got a new ring to connect the filter wheel and got first light on the whole new setup, try 3, on January 20, 2024, and I got data for both M42 the Orion Nebula and M101 the Pinwheel Galaxy which I could compare to previous images taken with my Canon 60D DSLR.  I appreciated the ASiair being able to configure a whole run including switching filters and have it automatically run.  I also appreciated the ASiair connecting to my iPad so I could see each image on my iPad from inside my house where it was warm!  I did still go outside to watch the telescope meridian flip to make sure no wires were caught. 

Here is the processed M42 Orion Nebula RGB image (dated 20 January 2024) with a previous DSLR image in the slideshow. The differences are hard to see and may be related to processing.

Camera geek info:

  • Williams Optics Zenith Star 73 III APO telescope
  • Williams Optics Flat 73A
  • ZWO 2” Electronic Filter Wheel
  • Antila RGB filters
  • ZWO ASI183MM-Pro-Mono camera
  • ZWO ASiair Plus
  • iOptron CEM40
  • Friendswood, Texas Bortle 7-8 suburban skies

Frames:

  • January 20, 2024
    • RGB lights
      • 59 60 second Gain 50 R lights 
      • 60 60 second Gain 50 G lights 
      • 57 60 second Gain 50 B lights
    • 30 0.0417 second Gain 50 G flats (a setting goof)
    • 30 0.0417 second Gain 50 B flats (a setting goof)
    • 28 0.05 second Gain 50 R flats
    • 30 0.05 second flat darks
    • 6 60 second darks

Processing geek info:

  • PixInsight
  • BlurXterminator
  • NoiseXterminator
  • StarXTerminator
  • Generalized Hyperbolic Stretch

Here is the processed M101 the Pinwheel Galaxy RGB image (dated 20 January 2024) with previous DSLR images in the slideshow. Here, the improvement is obvious, with significantly more detail in the galaxy with the new camera.  It even compares well to images taken from the much darker Dell City skies (February 2023 and June 2023).

Camera geek info:

  • Williams Optics Zenith Star 73 III APO telescope
  • Williams Optics Flat 73A
  • ZWO 2” Electronic Filter Wheel
  • Antila RGB filters
  • ZWO ASI183MM-Pro-Mono camera
  • ZWO ASiair Plus
  • iOptron CEM40
  • Friendswood, Texas Bortle 7-8 suburban skies

Frames:

  • January 20, 2024
    • RGB lights
      • 59 60 second Gain 50 R lights 
      • 60 60 second Gain 50 G lights 
      • 57 60 second Gain 50 B lights
    • 18 0.05 second Gain 50 R flats
    • 24 0.05 second Gain 50 G flats 
    • 17 0.05 second Gain 50 B flats
    • 30 0.05 second flat darks
    • 6 60 second darks

Processing geek info:

  • PixInsight
  • BlurXterminator
  • NoiseXterminator
  • StarXTerminator
  • Generalized Hyperbolic Stretch

I’m really pleased with this new equipment, and I’m looking forward to seeing what I can do with it!