SaratogaSkies Jim Solomon's Astropics

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M101 (Pinwheel Galaxy)   [obsolete]

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: Celestron C8-N (8" f/5 Newtonian)
Configuration: Prime Focus
Additional Optics: Celestron/Baader Multi Purpose Coma Corrector (MPCC)
Filter: None
Effective Focal Length: 1000mm
Effective Focal Ratio: f/5
Exposure: 88 x 4min @ ISO 400
Total Exposure: 5hrs, 52min
Date: 5/25/2006 11:02:17 PM PDT (start) and 5/29/2006 10:31:17 PM PDT (start)
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: GADFly 1.0.5
Guiding: GuideDog via Philips ToUcam Pro II (840k) through Orion ST80 w/ Celestron 2x "Kit" Barlow

Processing:

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

Image Description:

This is M101, aka, the Pinwheel Galaxy, a stunning spiral galaxy in the constellation of Ursa Major. For some strange reason, this version — with just shy of 6 total hours of expsoure over two nights — came out better than this old version with 32min of exposure time. <grin> I may go back and add some Hα data to this RGB image in order to bring out some of the features; namely, the areas with NGC designations which can be seen by mousing-over the image above. A higher-resolution image is also available. North is up.

 
M20 (Trifid Nebula)
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:

M20 (Trifid Nebula)   [obsolete]

Image Details:

Camera: Canon Digital Rebel (300D)
Mount: Celestron AS-GT
Scope: Celestron C8-N (8" f/5 Newtonian)
Configuration: Prime Focus
Additional Optics: n/a (Prime)
Filter: None
Effective Focal Length: 1000mm
Effective Focal Ratio: f/5
Exposure: 24 x 1min @ ISO 800
Total Exposure: 0hrs, 24min
Date: 7/11/2004, ~1:30am PDT
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: None
Guiding: None

Processing:

  • IRIS: Dark subtraction, flat frame, registration, and Kappa-Sigma stacking
  • Photoshop: Noise reduction, crop (1/2 x), image scale (1/2 x), JPG conversion

Image Description:

Another stunning object in the "summer" Milky Way. This is the Trifid Nebula, yet another gem in the constellation of Sagittarius. This is a Sigma stack of the best 24 of the 30 frames (the remaining 6 showed trailing/smearing due to tracking error). Interestingly, "dark subtraction" yielded a worse image than just stacking the un-dark-subtracted frames. I need to look into this. North is up.