SaratogaSkies Jim Solomon's Astropics


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December: Test shots with new scopes/mounts

Dec 21: TMB 80/480 Arrives!

Dec 3: AP1200 Arrives!

Nov 30: TMB 152/1200 Arrives!


M13 (Great Cluster in Hercules)   [obsolete]

Image Details:

Camera: Canon Digital Rebel (300D)
Mount: Celestron AS-GT
Scope: Celestron C8-N (8" f/5 Newtonian)
Configuration: Negative Projection (Barlowed)
Additional Optics: TeleVue 2x Barlow
Filter: None
Effective Focal Length: 2844mm
Effective Focal Ratio: f/14.2
Exposure: 12 x 1min @ ISO 3200
Total Exposure: 0hrs, 12min
Date: 6/23/2004 12:52am PDT (start)
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: None
Guiding: None


  • IRIS: Dark subtraction, flat field, registration, stacking, Richardson-Lucy Deconvoultion (5 iterations), AF5 Noise Reduction
  • Photoshop: Image scale (1/4x), JPG conversion

Image Description:

This magnification pushes the limits of my mount, especially without [auto]-guiding. Only 12 of the 32 frames were useable. The rest showed severe smearing/trailing and had to be tossed. This is a scaled version of the full-size frame. North is up.