Olympus's OM super-telephoto — the F.Zuiko Auto-T 600mm f/6.5 for extreme reach.
The Olympus OM-System F.Zuiko Auto-T 600mm f/6.5 is a super-telephoto for the Olympus OM mount, dating from 1972 and the early OM-System range. The F.Zuiko prefix is Olympus's element-count code and the Auto-T token marks the automatic diaphragm. It provided extreme reach for wildlife and distant subjects while keeping the aperture modest to limit size and weight.
This is a manual-focus Olympus OM lens with a 600mm focal length and a maximum aperture of f/6.5, designated F.Zuiko Auto-T. The slow aperture kept a 600mm lens within manageable proportions for the compact OM system. The verifiable specifications are the 600mm focal length, the f/6.5 maximum aperture and the manual-focus OM mount; element count, filter arrangement and weight are omitted rather than guessed.
A 600mm super-telephoto delivers dramatic reach and compression, ideal for birds, distant wildlife and subjects that cannot be approached. At this focal length careful support and technique are essential, and the f/6.5 aperture calls for good light or fast film. Used properly it fills the frame with far-off subjects that shorter lenses cannot resolve.
This super-telephoto is scarce and appears only occasionally, so prices reflect its specialist appeal. Inspect the large glass carefully for haze, fungus and separation, and confirm the aperture blades are dry and clean. Test the long focus travel for smooth resistance and verify the tripod mount and any filter arrangement. It can be adapted to mirrorless for extreme reach, though its size, weight and slow aperture demand steady support.