SaratogaSkies Jim Solomon's Astropics


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M17 (Omega 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: 30 x 1min @ ISO 800
Total Exposure: 0hrs, 30min
Date: 7/12/2004, ~11pm PDT
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: None
Guiding: None


  • IRIS: Dark subtraction, flat frame, registration, and Kappa-Sigma stacking
  • Photoshop: Color mixing, Image scale (1/4 x), JPG conversion

Image Description:

Yet another stunning object in the "summer" Milky Way. This is the Omega Nebula (aka Swan Nebula) in the constellation of Sagittarius. This is a Sigma stack of the best 30 of the 42 frames (the remaining 12 showed trailing/smearing due to tracking error). I cranked up the red a bit in Photoshop to compensate for the Digital Rebel's poor sensitivity to Hα, the main wavelength emitted by nebula such as this one. The real solution to this problem is to hack apart the camera and remove the IR filter ... in other words, destroy the camera. No thanks. North is up.