Olympus's vintage telephoto zoom — the Zuiko 85-250mm f/5 for the OM system.
The Olympus Zuiko 85-250mm f/5 Auto-Zoom is a vintage telephoto zoom from the Olympus OM mount system. Covering a useful telephoto range with a constant f/5 aperture, it provided OM system users with versatile telephoto reach. The constant aperture design ensures consistent exposure throughout the zoom range, a professional touch for the era.
Optical performance is adequate for the era. Sharpness is acceptable in the centre throughout the range. The constant f/5 aperture is slow but consistent. As an Olympus Zuiko lens, the optical quality is respectable — Olympus was known for producing excellent optics even in their zoom range. Colour rendition has the characteristic warm Zuiko quality.
Olympus OM mount, manual focus. Filter thread is 55mm. Weight is approximately 700 grams — heavy for the OM system, which prioritised compact design. Build quality is excellent with the precision metal construction typical of Zuiko lenses. The Auto-Zoom designation indicates compatibility with Olympus's automatic diaphragm system.
Uncommon on the used market. Check for smooth zoom and focus operation, and clean optics. The constant f/5 aperture limits practical use in low light. Primarily of interest to OM system collectors. For practical telephoto work, the Zuiko 75-150mm f/4 or individual Zuiko telephoto primes are better OM-system alternatives.