SaratogaSkies Jim Solomon's Astropics


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NGC 884 & NGC 869 (Double Cluster)

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

Image Details:

Camera: Mofidied Canon Rebel XT (350D): Hutech Type I Filter Replacement
Mount: Celestron AS-GT
Scope: Orion ED80 (80mm f/7.5 APO Refractor)
Configuration: Focal Reduced
Additional Optics: TeleVue #TRF-2008, 0.8x Reducer/Flatener For TV-85 And TV-76
Filter: None
Effective Focal Length: 480mm
Effective Focal Ratio: f/6
Exposure: 13 x 4min @ ISO 400
Total Exposure: 0hrs, 52min
Date: 11/12/2005 11:06:31 PM PST (start)
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: GADFly 1.0.5
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, cropping, JPG conversion

Image Description:

This is NGC 884/869, aka, the Double Cluster in Perseus. This shot was a test of the suitability of the TeleVue 0.8x Focal Reducer/Flatener for use with the Orion ED80 refractor. (Big thanks to Jim Nomura for letting me borrow the TeleVue!) This test was prompted by my disatisfaction with the combination of the ED80 and the Celestron 0.63x reducer which, of course, was never designed to be used with a refractor. (An example of the Celestron can be seen in my latest M31 shot.)

I've added this current shot, and the M31 shot, to my ED80 Reducer Shootout page. Based on this data, the Willam Optics Focal Reducer appears to be the best fit for the ED80. Time to trade in the Celestron. <grin>

Anyway, this shot turned out ok, despite a 91% full moon. And I have very few images of Open Clusters, so I decided to post this one. A higher-resolution image is also available. North is up.