SaratogaSkies Jim Solomon's Astropics

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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

Processing:

  • 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.

 
NGC 7023 (Iris Nebula)
SaratogaSkies Jim Solomon's Astropics

Search

Latest news

December: Test shots with new scopes/mounts

Dec 21: TMB 80/480 Arrives!

Dec 3: AP1200 Arrives!

Nov 30: TMB 152/1200 Arrives!

Links:

NGC 7023 (Iris Nebula)

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: 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: 42 x 4min @ ISO 400
Total Exposure: 2hrs, 48min
Date: 10/29/2005 9:28:47 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

Processing:

  • IRIS: Dark subtraction, registration, gradient removal
  • JimP: Flat field, Kappa-Sigma Stacking, White balance, ASINH stretching
  • Neat Image: Noise reduction
  • Photoshop: Levels, cropping, JPG conversion

Image Description:

This is NGC 7023, aka the Iris Nebula, in the constellation of Cepheus. This is my first auto-dithered image, using an adaptation of GADFly, originally written by TG Tan. The transparency was pretty lousy the night this was shot, and removing the background gradient was quite a challenge. A higher-resolution image is also available. North is up.