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photo:olympusom500mm

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Olympus OM 500mm f/8.0 mirror lens

see also:

introduction

  • this super telephoto lens introduced in 1982 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
  • the Olympus OM model is well recognised as being optically among the best made for 35mm cameras
  • it is substantially smaller and lighter than the Canon FD Reflex 500mm f/8.0 mirror lens and unlike the FD lens, it can be used on Canon EOS full frame cameras and can use conventional filters
  • in 1982 it was priced at $A620 which was more expensive than the OM 300mm f/4.5, just a touch cheaper than the 35mm shift lens and half the price of the OM 400mm f/6.3 lens.

specs

  • 500mm focal length and field of view (5°) at infinity focus (but gradually changes to 320mm when closer focus at 4m - this may be an issue with cameras where you need to set a focal length for the image stabiliser to work optimally)
  • fixed f/8.0 aperture
  • 5 elements in 2 groups (multicoated)
  • closest focus 4m which gives 19cm x 28cm (7.5“ x 11.0”) field of image
  • 72mm filter thread but mount turns when you focus
  • built-in sun-shade / lens hood
  • 81mm diameter, 97mm long and 590g (compare this with 255mm and 1.3kg for a 400mm refractor style lens)
  • if using on an OM SLR, the f/8 dim image is best managed by using a Type 1-4 focusing screen

reviews

photo/olympusom500mm.txt · Last modified: 2014/05/15 03:41 by gary1