Olympus's OM telephoto zoom — the Zuiko Auto-Zoom 50-250mm f/5, normal to long reach.
The Olympus OM-System Zuiko Auto-Zoom 50-250mm f/5 is a telephoto zoom for the Olympus OM mount, introduced in 1985. The Auto-Zoom token marks the automatic diaphragm. It covered a wide telephoto range from normal to substantial reach in a single lens, giving OM photographers a flexible long zoom for wildlife, sport and travel.
This is a manual-focus Olympus OM zoom with a 50-250mm focal range and a constant maximum aperture of f/5, designated Auto-Zoom. The constant f/5 aperture holds across the long range, which aids manual exposure. The confirmed specifications are the 50-250mm focal range, the constant f/5 maximum aperture and the manual-focus OM mount; element count, filter thread and weight are omitted here rather than stated without verification.
A 50-250mm zoom spans from normal to strong telephoto, covering portraits at the short end and distant subjects at the long end without changing lenses. It suits wildlife, sport, travel and general telephoto work where flexibility matters. The constant f/5 aperture asks for reasonable light but keeps the lens practical, making it a useful single-lens telephoto solution.
This telephoto zoom is moderately common and generally affordable on the used market. Check the glass for haze, fungus and internal dust, which longer zooms can accumulate, and confirm the aperture blades are dry and clean. Test the zoom and focus actions for smooth travel with no play, and verify the aperture ring clicks positively. It adapts to mirrorless as a versatile telephoto zoom, though its slower aperture is a consideration in low light.