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The Crescent Nebula in Cygnus


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Hi,

many forums and the "pros" once were certain that the star eater issue makes the Sony A7 Series unusable for astrophotography but I always had good results with my Sony A7rII. So I recently went ahead and had it astromodified. The thick IR-Block Filterglas was replaced with a thin Baader substitute that lets IR Light down to the h-alpha line and the sII line through to the sensor with high transmission. The results can be seen in detail on my google drive link here:

https://drive.google.com/file/d/1SrdJ7tJbEUwN5KcbXsfpKaesq8KltzmY/view?usp=sharing

I could write a lot of things that make the A7rII not the perfect camera for astro but suffice to say, it is still bloody capable. Cheers and CS,

Ben - Instagram - AstroBin

Technical stuff:

Acquisition:

  • Imaging telescope or lens : Meade SN-8
  • Imaging camera : Sony a7rII astro modified
  • Focal reducer : TeleVue ParaCorr PLU1106
  • Filter : STC Cyclops Optics STC Astro Duo-Narrowband Filter
  • Dates : May 28, 2020
  • Frames : STC Cyclops Optics STC Astro Duo-Narrowband Filter :  39x300" ISO640
  • Integration : 3.2 hours
  • Darks : ~50
  • Flats : ~50
  • Avg. Moon age : 5.67 days
  • Avg. Moon phase : 32.16%
  • Bortle Dark-Sky Scale : 8.00

Processing was done with Adobe Lightroom Classic CC, Aries Productions Astro Pixel Processor APP and Adobe Photoship CC 2018. Stacked with sigma kappa clipping 3/1. Light pollution could not be removed automatically in A.P.P. and had to be done manually in Lightroom with local adjustments and a lot of fiddling. Both images have reduced star sizes with a minimum filter applied to masked stars. The masked stars color’s were also tweaked in order to bring them close to the feel of a normal broadband rgb distribution with colors between either aqua and blue or yellow and orange. I did however not manage to create a mask that includes the faintest and smallest of stars. If you look closely you see how the star colors are a little off, the smaller the stars get

crescent_nebula_3h-Edit-2.jpg

Edited by Ben
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