Astrophotography – Equipment

Equipment

  • Any digital camera with:
    • Manual focussing
    • Long exposure settings (preferably “B”)
    • A Digital SLR would meet these requirementsPicture1
  • A good tripodPicture4
  • Remote release (or timer release) to start and stop exposures without shaking the cameraPicture3
  • Optional:
    • A range of interchangeable lenses for DSLR (Prices from £50-thousands (or buy 2nd hand))
    • Mirror lockup
    • Approved Solar Filter for solar use

Digital SLRs

  • Allow interchangeable lenses and direct attachment to telescopes
  • Provide many more features to directly control the camera and image
  • Two main types
    • Full Frame (36mmx24mm) Prices £2000 and above (Canon 1D, 5D, 6D; Nikon FX models)
    • APS-C ~22mm x15mm Prices £250 to £1500 (Canons 7D and with x0D;x00D;xx00D; Nikon DX Models
    • Canon sell the 60Da specifically for astrophotography
      • Replaces the IR filter so more sensitive to red light emitted by Hydrogen in deep space
      • Possible to modify other DSLRs but invalidates warranty!

Exposures

  • Automatic settings on cameras will not deal with very low and extreme light levels
    • Use Manual Exposure setting
  • Need to get as much light onto the sensor as possible
  • Exposure length
    • Must be tripod mounted
    • Star trailing on long exposures
  • Focal Ratio (f) – lens aperture divided by focal length
    • Open at widest (but may see aberrations – 1 stop down if so)
    • Very fast lenses (< f2) are more expensive
  • ISO – increases the sensitivity of the sensor with electronics
    • More noise at higher ISO as sensor gets hotter
    • More modern DSLRs are less noisy at higher ISO settings

Lenses

Picture2

  • Any DSLR lens is potentially useful
    • Wide Angle (10mm-~40mm)
      • Good for long exposure star fields, milky way, meteors, aurora,ISS
      • Most DSLRs come with an 18mm-55mm lens
    • “Prime” lens – around 50mm
      • Typically faster lenses for shorter exposures and have better optics (and more expensive)
    • Telephoto (100mm-500mm)
      • Show more detail
      • Star trailing at short exposures (<1sec)
      • Zoom lenses give more flexibility and affordabilityPicture5

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