SaratogaSkies Jim Solomon's Astropics


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NGC 6888 (Crescent Nebula)   [obsolete]

Image Details:

Camera: Canon Digital Rebel (300D)
Mount: Celestron AS-GT
Scope: Celestron C8-N (8" f/5 Newtonian)
Configuration: Prime Focus
Additional Optics: n/a (Prime)
Filter: None
Effective Focal Length: 1000mm
Effective Focal Ratio: f/5
Exposure: 9 x 10min @ ISO 100
Total Exposure: 1hrs, 30min
Date: 8/14/2004, ~3am PDT
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: None
Guiding: GuideDog via Philips ToUcam Pro II (840k) through Orion ST80 w/ Celestron 2x "Kit" Barlow


  • IRIS: Dark subtraction, flat field, registration, Kappa-Sigma stacking
  • Photoshop: Levels, image size, cropping, JPG conversion

Image Description:

This is NGC 6888, the Crescent Nebula, in the constellation of Cygnus and is my first autoguided photo; first, that is, with my own guiding equipment. I still haven't mastered the guiding software, so there was a bit of smearing on some of these frames, but all were decent and useable. The conditions were quite awful though, with rather horrid transparency and seeing, and clouds moving in and out. An object this faint requires pretty pristine conditions. This is a 50% crop of the full frame, scaled for display on the web. North is up.