Astronomical Photographs I have taken

• Oct 17, 1997: RIT Observatory grounds. Moon via afocal projection with Astroscan and telephoto lens.

• Unguided and piggyback exposures with 28mm and telephoto lenses, Aug/Sept 1998. I learned the following (for ASA 1600 film):
  1. at f/5.6, a 300-second exposure starts to pick up background sky. Even longer exposures might be better.
  2. using 200mm f/5.6 lens, 300-sec exposure goes to maybe mag 10; much deeper than Skalnate Pleso
  3. using 200mm f/5.6 lens, 90-sec exposure goes to maybe mag 8.5; slightly deeper than Skalnate Pleso
  4. using 28mm f/2.8, 60-sec exposure goes to maybe mag 7.5; about the same as Skalnate Pleso
  5. 200mm lens shows M13 as slightly non-stellar, shows M22 as distinctly triangular in shape
  6. sky at RIT observatory is bright; 90 sec at f/2.8 near S horizon produces background which is a bit too bright; 60-90 sec exposures probably best for wide-angle views of sky
  7. using 28mm f/2.8 lens, exposures of 10-20 sec show constellations at roughly naked-eye limit from RIT
  8. some piggyback exposures show evidence for "bouncing" or "jiggling" of the camera during exposure. Must be very careful not to bump telescope, or yank on cable release. Probably a good idea to use hat or cardboard to cover lens as mirror flips up at start and end of exposure.

• Images of Jupiter and Saturn taken by Anne Young, using the Meade 10-inch f/10 and ASA 1600 film.
  • Jupiter's clouds best around 1/250
  • Galilean satellites may be compared in brightness at 1/2
  • Saturn's clouds maybe reasonable around 1/15 - 1/60?
  • Saturn's moons may be compared in brightness at 4-10 sec