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photo:pentaxsmc400-600mm

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Pentax SMC 400-600mm f/8-12 Reflex Zoom mirror lens

introduction

  • this super telephoto lens introduced in ? is a catadioptric mirror lens, and as with all such mirror lenses, share the following characteristics:
    • manual focus
    • fixed aperture (in this case f/)
    • 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

specs

  • 400-600mm focal length and field of view (2.5°) at infinity focus
  • fixed f/8-12 aperture (varies with zooming)
  • 12 lens elements, 7 groups
  • closest focus 3m (0.4x macro)
  • 67mm front filter
  • 40.5mm rear filter thread
  • Pentax K lens mount
  • 82mm diameter, 108mm long and 730g

reviews

photo/pentaxsmc400-600mm.txt · Last modified: 2014/05/18 09:30 by gary1