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December: Test shots with new scopes/mounts
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NGC 6888 (Crescent Nebula)
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Image Details:
- Camera: Mofidied Canon Rebel XT (350D): Hutech Type I Filter Replacement
- Mount: Celestron AS-GT
- Scope: Celestron C8-N (8" f/5 Newtonian)
- Configuration: Prime Focus
- Additional Optics: Celestron/Baader Multi Purpose Coma Corrector (MPCC)
- Filter: None
- Effective Focal Length: 1000mm
- Effective Focal Ratio: f/5
- Exposure: 20 x 8min @ ISO 400
- Total Exposure: 2hrs, 40min
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- Date: 10/3/2005 10:12:08 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
Processing:
- IRIS: Dark subtraction, registration, gradient removal
- JimP: Flat field, Kappa-Sigma Stacking, White balance, ASINH stretching
- Photoshop: Levels, cropping, JPG conversion
Image Description:
This is NGC 6888, aka the Crescent Nebula in the constellation of Cygnus. While the modified camera does an excellent job of capturing Hα, an object like this needs addition Hα-only exposures to improve the contrast against its busy background. Something for another day. A higher-resolution version of this image is also available, as is my previous attempt from last year with an unmodified camera. Note how much more Hα the modified camera records. North is up.