Equipment details:

  • Mount: OpenAstroMount by OpenAstroTech
  • Lens: Sony 200-600 @ 600mm f/7.1
  • Camera: Sony A7R III
  • Guidescope: OpenAstroGuider (50mm, fl=163) by OpenAstroTech
  • Guide Camera: SVBONY SV305m Pro
  • Imaging Computer: ROCKPro64 running INDIGO server

Acquisition & Processing:

  • Imaged and Guided/Dithered in Ain Imager
  • 420x30s lights, 40 darks, 100 flats, 100 biases, 100 dark-flats over two nights
  • Prepared data and stacked in SiriLic
  • Background extraction, photometric color calibration, generalized hyperbolic stretch transform, and StarNet++ in SiriLic
  • Adjusted curves, enhanced saturation of the nebula and recombined with star mask in GIMP, desaturated and denoised background

This is my first time doing a multi-night image, and my first time using SiriLic to configure a Siril script. Any tips there would be helpful. Suggestions for improvement or any other form of constructive criticism are welcome!

  • KingRandomGuy@lemmy.worldOPEnglish
    2·
    8 months ago

    Thank you for the feedback!

    I think you may want to increase your dither size (or do them more often)

    Good catch! What happened was that I forgot to tick the box to enable dithering on the first night, so the first ~180 subs or so had no dithering at all, which definitely caused the pattern noise. That said, I’d be interested to hear if you know of a rule of thumb for dithering settings (i.e. how frequently should you dither, and how many pixels). When I was dithering on the second night, I dithered every 2 frames by 2 pixels, but I more or less picked those values arbitrarily.

    Also if your tracking allows for some longer subs, you could try to HDR those with your 30" exposure

    Gotcha, I’ll give that a try next time. I’m shooting with an unmodified and unfiltered camera from an urban area (Bortle 7-8) so I figured longer exposures wouldn’t help too much, but it sounds like it might still be worthwhile. Thanks for the tip!

    • lefty7283@lemmy.worldMEnglish
      2·
      8 months ago

      If I’m shooting just one filter I usually dither every 4 frames, but most of the time I loop LLLRRGGBB > dither or HaHaOiiiOiiiSiiSii> dither. Imo dithering every 2 frames is a lot as you’ll spend a lot of time waiting for it to settle and not actively imaging.