Carl Zeiss Contax 500mm f/8.0 Mirotar T* mirror lens

see also:

• super telephoto mirror lenses

• this super telephoto lens is a catadioptric mirror lens, and as with all such mirror lenses, share the following characteristics:
  • manual focus
  • fixed aperture (in this case f/8.0)
  • virtual elimination of chromatic aberration as uses mirror rather than lenses
    • also means focus position for infrared photography is the same as for light photography
  • central mirror:
    • allows much more compact lens length as the optic path is reflected internally twice
    • by necessity, blocks some of the light and thus causes:
      • decrease in image contrast
      • characteristic “doughnut” shaped bokeh imagery in out of focus areas

• 500mm focal length and field of view (4.9°)
• fixed f/8.0 aperture
• 4 groups, 6 elements (including mirror), T* multicoating
• closest focus 3.5m
• 82mm front filter thread
• mm diameter, mm long and 795g (compare this with 255mm and 1.3kg for a 400mm refractor style lens)
• ~50% heavier and bigger than the Olympus OM 500mm f/8.0 mirror lens

• http://www.contaxcameras.co.uk/slr/slrmanlenses/mirotar5008.html