Astrophotography: With a telescope, DSLR and webcam

  • Extra Equipment

–Telescope (obviously) Picture6

–T Ring and Adapter to attach Camera Picture7

–Tele-extender for eyepiece projection Picture10

  • Optional

–Solar Filter (essential for observing the Sun)

–Focal Reducer

–Light Pollution filter

–Narrowband filters (H-alpha, H-beta, O-III….)

–Bhatinov Mask (for focussing)

–Autoguider (necessary for long exposures >1 min)


Prime Focus:

  • Connect Camera to the Telescope where the eyepiece would normally be housed
  • Look through the camera to focus (use LiveView if available)
  • Can improve focus with Bhatinov Mask
  • Focus on a bright star first
  • Bright objects (Moon, Sun, bright planets) need short exposures so precise alignment not necessary
  • Objects such as Nebulae and Galaxies outside the Solar System
  • Deep Sky Objects require long exposures
  • Most telescopes need auto-guiding for exposures above 30-60s (even polar aligned ones)
  • Fortunately software helps!
  • Take many shots of 30s-60s and use software to align and stack to bring out detail
  • Also uses “dark frames” to remove some noise from the images
  • But faint objects need longer exposures: AutoGuiding (an advanced topic)
  • Take multiple images and “dark” frames
  • Use software to stack the images to improve signal to noise
  • Free Software

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