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!


M57 (The Ring Nebula in Lyra)   [obsolete]

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: 13 x 1min @ ISO 3200
Total Exposure: 0hrs, 13min
Date: 6/23/2004, ~3am PDT
Location: Saratoga, CA, USA
Acquisition: DSLRfocus
Focus: DSLRFocus
Dithering: None
Guiding: None


  • IRIS: Dark subtraction, flat field, registration, stacking
  • Photoshop: Noise reduction, levels, cropping, JPG conversion

Image Description:

This magnification pushes the limits of my mount, especially without [auto]-guiding. Only 13 of the 32 frames were useable. The rest showed severe smearing/trailing and had to be tossed. This is a crop of the full-size frame. North is up.

In the "trip down memory lane" category, here is an old image I captured back when I first got my scope and borrowed a friend's Nikon D100. This was 20mm eyepiece projection (1910mm, f/9.6), 1 x 2min exposure @ ISO 1600, dark-frame subtracted and processed in Photoshop. I think my technique has come a long way since then!