SaratogaSkies Jim Solomon's Astropics

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NGC 6210 (Planetary Nebula)

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: 88 x 60sec @ ISO 800
Total Exposure: 1hrs, 28min
Date: 7/14/2004, 11:30pm PDT
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: None
Guiding: None

Processing:

  • IRIS: Dark subtraction, flat field, registration, Kappa-Sigma stacking, Wavelet processing
  • Photoshop: Compositing, cropping, JPG conversion

Image Description:

NGC 6210 is a planetary nebula in the constellation of Hercules. I used IRIS's Wavelet Processing capabilities to bring out details in the nebula. However, that made the surrounding stars and the sky background look icky, a technical term. So I used Photoshop to composite the wavelet-processed nebula with a non-wavelet-processed background using layer masks. There, I feel much better for coming clean. <g> Also, I was very careful at every step of the aquisition and processing chain not to clip any of the nebula or its central star, in order to preserve the color and appearance of the nebula. This is a crop of the full-size image. North is up.

 
M13 (Great Cluster in Hercules)
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:

M13 (Great Cluster in Hercules)

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Image Details:

Camera: SBIG ST-2000XM
Mount: Astro-Physics 1200GTO
Scope: AP Starfire 160EDF APO Refractor
Configuration: Prime Focus
Additional Optics: n/a (Prime)
Filter: Astrodon LRGB I-Series Filters
Effective Focal Length: 1200mm
Effective Focal Ratio: f/7.5
Exposure: 8 × 8min @ -20°C (Lum); {16R, 16G, 16B} × 2min @ -15°C
Total Exposure: 2hrs, 40min
Date: 6/10/2008 11:37 PM; 7/25/2009 11:12 PM (Start)
Location: Saratoga, CA, USA
Acquisition: CCDSoft
Focus: FocusMax
Dithering: None
Guiding: Self Guided

Processing:

  • IRIS: Registration, gradient removal
  • JimP: Dark subtraction, Flat field, Kappa-Sigma Stacking, White balance, LRGB combining, ASINH stretching
  • Photoshop: JPG conversion

Image Description:

This is M13, aka, the Great (globular) Cluster in Hercules. I captured the RGB of this image with the TMB 152/1200, and the Luminance about a year later with the AP 160 Starfire EDF. The RGB was taken on a pretty icky night, with FWHMs well over 3”. But the Luminance exposures, taken through the exquisite AP 160, all had sub-2” FWHMs, on a night of fantastic seeing, at least for my location. Some minor DEC backlash adjustments resulted in pretty good guiding too. Note that there is absolutely no sharpening applied to this image. All in all, this is by far my best image of a globular cluster. A higher-resolution image is also available. North is up.