SaratogaSkies Jim Solomon's Astropics


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SH 2-27 (Emission Nebula East)

Mouse-over to see annotations. (Requires Javascript) Click to see high-res version.

Image Details:

Camera: Mofidied Canon Digital Rebel (300D): Hutech (no filter)
Mount: Celestron AS-GT
Scope: Canon EF 200mm f/2.8L II USM lens
Configuration: Prime Focus
Additional Optics: n/a (Prime)
Filter: None
Effective Focal Length: 200mm
Effective Focal Ratio: f/2.8
Exposure: 33 x 4min @ ISO 200
Total Exposure: 2hrs, 12min
Date: Date: 7/2/2005 9:44:35 PM PDT (start)
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: Manual
Guiding: GuideDog via Philips ToUcam Pro II (840k) through Orion ST80 w/ Celestron 2x "Kit" Barlow


  • IRIS: Dark subtraction, registration, gradient removal
  • JimP: Flat field, Kappa-Sigma Stacking, White balance, ASINH stretching
  • Photoshop: Levels, image scale, cropping, clone tool, JPG conversion

Image Description:

This is the Eastern portion of SH 2-27, a very large but very faint emission nebula in the constellation of Ophiuchus. Thanks much to Rich S. for letting me borrow his Modified 300D, without which I would not have been able to capture any of the red Hα nebulosity. Unfortunately, only after the fact, did I discover that there was a pretty obnoxious globber on the camera's sensor that moved (!) between the time I captured the Lights and Flats, so I had to do some unholy clone-tool operations in Photoshop to clean it up. There, I feel much better for coming clean on this. <grin>

Move your mouse over the image above to see annotations of the various dark-nebula regions, or click on the image for a higher-resolution version. The image above is the full frame, shrunk for display on the web. North is right.