SaratogaSkies Jim Solomon's Astropics


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!


M8/M20 (Widefield)

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: 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: 16 x 4min @ ISO 200
Total Exposure: 1hrs, 4min
Date: 8/23/2005 9:07:47 PM PDT (start)
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: Manual
Guiding: GuideDog via Philips ToUcam Pro II (840k) through Orion ST80 w/ Celestron 2x "Kit" Barlow


  • IRIS: Dark subtraction, registration
  • JimP: Flat field, Kappa-Sigma Stacking, White balance, ASINH stretching
  • Photoshop: Levels, image scale, JPG conversion

Image Description:

This is "First Light" for my brand-spanking-new Canon EOS Digital Rebel XT (350D), modified by Hutech to remove Canon's standard "IR Blocking" filter which, unfortunately, blocks a lot more than Infrared. In particular, it blocks much of the Hα wavelength, that deep red color found in emission nebulae et. al., which is so prominent throughout the universe. This Hutech mod is a replacement of that standard filter with their Type I astronmical filter which only blocks IR and UV but lets the Hα wavelength pass. The camera was a 40th Birthday present from my dear wife, Lyena. She totally rocks!

Anyway, this is a well-traveled field in Sagittarius containing two of the showcase Messier objects of summer: M8 (the Lagoon Nebula) and M20 (the Trifid Nebula), plus the NGC 6559 Region that Rich and I recently shot with his modified 300D. Moonrise limited the exposure time to just over an hour. More would have been better, but the reality is that this was just a test shot to make sure all of the hardware and software was functioning. This is the full frame, shrunk for display on the web. A full resolution image is also available. North is right.