photo:sigma600mmf8
Table of Contents
Sigma 600mm f/8.0 mirror lens
see also:
introduction
- 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
specs
- 600mm focal length and field of view (4.2°)
- fixed f/8.0 aperture
- 3 groups, 6 elements (including mirror), multicoating
- closest focus 1:3 macro
- 86mm front filter thread
- rear section filter holder, drop-in type (with 22.5mm exclusive filter)
- screw on sun-shade / lens hood
- 90mm diameter, 135mm long and 753g (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
reviews
photo/sigma600mmf8.txt · Last modified: 2014/05/18 02:10 by gary1