Olympus Zuiko Auto-Macro 90mm f/2

Most macro lenses of the early 1980s topped out at f/3.5 or f/4. Fine for a copy stand, useless for an available-light portrait. Olympus had built the OM system on the premise that a 35mm body could be smaller and more rationally laid out than the Nikon and Canon tanks of the decade, and Maitani's team kept sharpening the lens line through the 1980s. The 90mm f/2 Macro arrived in 1986 as the direct answer to that slow-macro complaint: a true macro you could also shoot wide open in a room.

At f/2 it is sharp in a way most fast lenses of the era were not. Center resolution is high right from maximum aperture, and contrast holds instead of going soft and milky the way a fast double-Gauss usually does wide open. Reviewers report the corners cleaning up as you stop down a stop or two. The rendering is clean and modern, correct rather than characterful, which is exactly what you want when the focus plane is paper-thin across a face or a flower. Out-of-focus areas are smooth and neutral, not swirly. Color is faithful, flare control is good, and the floating-element design keeps the field flatter than typical short teles when you focus close.

People shoot it for portraits as often as for true macro. The 90mm length flatters faces, f/2 throws the background well clear, and the built-in helicoid runs all the way to 1:2 magnification without a tube. Add the Olympus auto extension tube and you reach 1:1. It became a quiet favorite among nature and medical shooters who wanted a single lens that worked just as well on a clinical close-up as out in the field, and it has stayed a cult object among OM users ever since.

The honest catch is supply and price. Olympus made far fewer of these than the 50mm f/1.8 that came bolted to every body, so clean copies command real money, often more than a comparable Nikon or Canon macro of the same vintage. The other limitation is purely physical: this is a long lens that gets longer as it focuses close, so a steady hand or a tripod matters more than the f/2 figure suggests.

Down in macro range, remember the effective aperture drops as the lens extends. At 1:2 you are losing light a handheld meter never accounts for. Set the magnification or extension in Zone Light Meter and it folds the bellows factor into the exposure, so a metered Zone V lands where you placed it instead of coming back a stop dark. The filter thread is 55mm, a common size on several later Zuikos, so it may share NDs or a polarizer with some of your other OM glass. Cross-shopped today against the Tamron SP 90mm and the Nikon 105mm Micro, it wins on speed and loses on price, and the people who want OM rendering pay it.