SaratogaSkies Jim Solomon's Astropics


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M5 (Globular Cluster)

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Image Details:

Camera: Mofidied Canon Rebel XT (350D): Hutech Type I Filter Replacement
Mount: Celestron AS-GT
Scope: Takahashi Mewlon 180
Configuration: Prime Focus
Additional Optics: n/a (Prime)
Filter: None
Effective Focal Length: 2410mm
Effective Focal Ratio: f/13.4
Exposure: 17 x 4min @ ISO 400
Total Exposure: 1hrs, 8min
Date: 6/22/2007 11:41pm PDT
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: GADFly 1.0.5
Guiding: GuideDog via Philips ToUcam Pro II (840k) through Off-Axis Guider


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

Image Description:

This is M5, a globular cluster in the constellation of Serpens. This is my first shot through (at the time!) Drew's Takahashi Mewlon 180, which I ended up buying. It's a great little scope and wonderful for long focal length work. It suffers from coma off-axis, but it's an incredible on-axis performer. This image was off-axis guided wtih Rich's (thanks Rich!) Celestron Radial Guider. It prevented flexure from ruining the exposures. A higher resolution image is also available. North is up.