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photo:prooptic500mmf5.6

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ProOptic Maksutov Cassegrain 500mm f/5.6 mirror telescope lens

introduction

  • this super telephoto lens is a Maksutov Cassegrain catadioptric mirror lens, and as with all such mirror lenses, share the following characteristics:
    • manual focus
    • fixed aperture (in this case f/5.6)
    • 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
  • this lens is designed as a telescope having a T2 screw mount to attach to cameras, but also a thumb screw to lock in eyepieces.
  • unlike photographic mirror lenses, it has a manual focus knob rather than the barrel acting as a manual focus control

specs

  • 500mm focal length and field of view (5°) at infinity focus
  • fixed f/5.6 aperture
  • closest focus 1.5m although this will require many rotations of the focus knob
  • filter thread ?95mm
  • no built-in sun-shade / lens hood
  • 105mm diameter, 220mm long and 1220g
  • a 105mm solar filter can be slid over the end for photographing the solar eclipse photography

reviews

photo/prooptic500mmf5.6.txt · Last modified: 2014/05/17 08:11 by gary1