Table of Contents

introduction
specs
reviews

Minolta Rokkor RF 250mm f/5.6 mirror lens

see also:

super telephoto mirror lenses

introduction

this is a very popular and now expensive mirror lens
this super telephoto lens introduced in 1979 is a catadioptric mirror lens, and as with all such mirror lenses, share the following characteristics:
- manual focus
- fixed aperture (in this case f/5.6)
- 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

250mm focal length and field of view (10° ??) at infinity focus
fixed f/5.6 aperture
6 lens elements, 5 groups (multicoated)
closest focus 2.5m (8.2')
62mm filter thread but mount turns when you focus + 39 mm rear filter
68mm diameter, 71mm long and 262g
Ebay prices tend to be $600-1200

reviews