Minolta AF Reflex 500mm f/8

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Minolta Reflex 500mm f/8
Maker Minolta, Sony
Technical data
Type Special Prime
Focal length 500 mm
Aperture (max/min) f/8 fixed
Close focus distance 4 m
Max. magnification 1/7.7
Diaphragm blades No blades, circular
Construction 7 elements in 5 groups
Ultrasonic motor No No
Macro capable No No
Unique features AF capable Mirror Lens
Application Telephoto
Max. length 118 mm
Weight 665 g
Filter diameter Front 82mm & Rear drop-in (Clear and NDx4)
Lens hood Front threaded
Angle of view
Horizontal 4.9°
Introduction 1989
Discontinuation 2010
Successor Minolta version succeeded by Sony version in 2006
Retail info
MSRP 699 USD (as of 2006)

Originally produced by Minolta, and until recently, produced by Sony, the AF Reflex 500mm f/8 is a catadioptric photographic lens compatible with cameras using the Minolta A-mount and Sony A-mount lens mounts.

The Minolta/Sony Reflex 500mm lens is the only production mirror lens designed to auto focus with an SLR camera. There are other mirror lenses that can mount onto current mounts such as Canon EF-mount and Nikon F-mount, but all of these mirror lenses are manual focus only. Only this lens can have its focus controlled by the camera's autofocus motor in conjunction with TTL autofocus sensing. In terms of the Minolta AF and subsequent Sony α SLR systems, this lens is an anomaly, being the only lens guaranteed to auto focus at f/8. Minolta also produced a V-mount 400 mm f/8 Reflex lens that can autofocus at f/8, but only the Minolta Vectis S-1, Minolta Vectis S-100 and Minolta Dimâge RD 3000 can use it.

The mirror design does not utilize aperture blades, and thus the aperture of the lens is fixed at f/8. Exposure may only be controlled by shutter speed, film or sensor sensitivity, or a rear-mounted neutral density filter.

By using a mirror design similar to that of a telescope, this lens uses very little glass compared to traditional telephoto lenses and is thus much smaller, lighter, and far less expensive than traditional lenses in the same focal length. However, this and all other mirror lenses can produce an undesirable donut-shaped bokeh in the image it produces.

See also[edit]