SaratogaSkies Jim Solomon's Astropics

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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: SBIG ST-2000XM
Mount: Astro-Physics 1200GTO
Scope: TMB 152/1200 APO Refractor
Configuration: Prime Focus
Additional Optics: n/a (Prime)
Filter: Astrodon Hα 6nm Filter
Effective Focal Length: 1200mm
Effective Focal Ratio: f/7.9
Exposure: 6 × 32min @ -15°C (Hα)
Total Exposure: 3hrs, 12min
Date: 6/12/2008 11:49 PM PDT (Start)
Location: Saratoga, CA, USA
Acquisition: CCDSoft
Focus: FocusMax
Dithering: Manual
Guiding: Self Guided

Processing:

  • IRIS: registration
  • JimP: Dark subtraction, Flat Field, Kappa-Sigma Stacking, ASINH stretching
  • Photoshop: JPG conversion

Image Description:

This is an Hα image of NGC 6888, aka, the “Crescent Nebula”, an emission nebula in the constellation of Cygnus. This is a “work in progress”, as I will be adding other emission-line data in the future. Check out my color DSLR shot to see this object in color. A higher resolution image is also available. North is up.

 
Fire (Henry Coe State Park)
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:

Fire (Henry Coe State Park)

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: None
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: 410 x 6sec @ ISO 200
Total Exposure: 0hrs, 41min
Date: 9/4/2007 10:30pm PDT
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: None
Guiding: None

Processing:

  • IRIS: Dark subtraction, PIC to BMP Conversion
  • JimP: Flat field, White Balance, ASINH stretch
  • BMP2PNG: BMP to PNG conversion
  • Mencoder: PNG to AVI movie encoding
  • Photoshop: Image scale, JPG conversion

Image Description:

This is a photo and animation (5 MB) of what threatens to become one of the largest wildfires in Santa Clara County history, according to the San Jose Mercury News. The images were captured from my house in Saratoga, roughly 35miles west of Henry Coe State Park, where the fire is centered.

While not really an astrophoto per se, the acquisition and subsequent processing of these images use the exact same process I've been using for DSLR imaging of the universe, including calibration (dark subtraction, flat fielding) and subsequent processing in IRIS and home-brewed software tools. Note, for example, the complete absence of checkerboard “pattern noise” in the background, as well as a complete lack of vignetting. In addition, Coe is one of the sites frequented by Bay Area astronomers seeking dark skies.

The animation (5 MB) is a time lapse, consisting of 410 stills taken with the DSLR, each a 6 second exposure with 5 seconds between them for mirror lockup (to avoid vibration) and for time to save the image to compact flash. Total time span is about 1 hour and 15 minutes.

A higher resolution image is also available. The camera is looking almost due East in this picture, with San Jose between the camera and the fire, but off-camera to the left (North).