Olympus's admired OM fast telephoto — the Zuiko Auto-T 100mm f/2, a superb portrait prime.
The Olympus OM-System Zuiko Auto-T 100mm f/2 is a fast short telephoto for the Olympus OM mount, introduced in 1987 as one of the later and most admired OM primes. The Auto-T token marks it as an automatic-diaphragm telephoto. It was designed as a high-speed portrait and available-light lens and is regarded as one of the finest optics Olympus made for the system.
This is a manual-focus Olympus OM lens with a 100mm focal length and a maximum aperture of f/2, designated Auto-T. The bright f/2 aperture in a 100mm telephoto was ambitious and demanded a sophisticated optical design. The confirmed specifications are the 100mm focal length, the f/2 maximum aperture and the manual-focus OM mount; element count, filter thread and weight are omitted here rather than stated without verification.
A fast 100mm is an excellent portrait focal length, giving a flattering perspective with strong subject isolation and smooth background blur at f/2. The speed also makes it capable in low light and for indoor and stage work. It renders skin tones and out-of-focus areas gently, which is why it earned such a strong following among OM portrait shooters.
This lens is one of the most sought-after OM telephotos, so it is scarce and commands high prices, with clean copies in strong demand. Inspect carefully for haze, fungus and separation, all of which hurt the value of a premium lens, and confirm the aperture blades are dry and snappy. Test the focus ring for smooth even travel. It is a highly prized adaptation on mirrorless for portraiture, so buyers should expect a premium and competition.