SaratogaSkies Jim Solomon's Astropics


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NGC 6804 (Planetary Nebula)

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Image Details:

Camera: SBIG ST-2000XM
Mount: Takahashi NJP
Scope: Takahashi Mewlon 180
Configuration: Prime Focus
Additional Optics: n/a (Prime)
Filter: Astrodon LRGB I-Series Filters
Effective Focal Length: 2160mm
Effective Focal Ratio: f/12
Exposure: L: 6 × 16min (1×1); RGB: 6 × 4min (3×3)
Total Exposure: 2hrs, 48min
Date: 9/14/2007 9:27pm PDT
Location: Saratoga, CA, USA
Acquisition: CCDSoft
Focus: CCDSoft
Dithering: Manual
Guiding: Self Guided


  • IRIS: Dark subtraction, registration, gradient removal
  • JimP: Flat field, Kappa-Sigma Stacking, White balance, LRGB combine, ASINH stretching
  • CCDSharp: Richardson-Lucy deconvolution
  • Photoshop: Neil's Trick, cropping, JPG conversion

Image Description:

This is NGC 6804, a planetary nebula n the constellation of Aquila. Had some tracking/focus/both problems in the acquisition of this image, but Neil Fleming's Star Trail Removal trick worked very well, after applying a generous dose of deconvolution in CCDSharp. This is an LRGB composite, with the Luminance binned 1×1 and the color data binned 3×3. A higher resolution image is also available. North is up.