Olympus Zuiko Auto-T 135mm f/2.8

Stand at the back of a small theater, or across a quiet street from someone who hasn't noticed you yet, and the 135mm focal length is exactly the reach you want. Long enough to pull a face out of a crowd without a 200mm's bulk swinging around your neck, short enough to hand-hold at 1/125 without praying. The Zuiko Auto-T 135mm f/2.8 is the lens Olympus built for that job, and on an OM body it disappears into your hand. That was the whole OM pitch in 1972: full-frame SLR performance in a kit you'd actually carry all day.

Optically it's a conventional telephoto design from the era, and it behaves like a good one. Wide open at f/2.8 it's sharp in the center and softer toward the corners, which is normal for a fast tele of this age and the price of that extra stop. Stop to f/5.6 and the frame tightens up corner to corner. Contrast is moderate, not the high-contrast slap of a modern multicoated lens, which is part of why it flatters skin. The out-of-focus rendering is smooth and fairly neutral, with the background falling away cleanly behind a head-and-shoulders portrait at the closer end of its range.

Color leans warm and faithful on slide film, and flare control is decent for a 1970s coating, though shoot it straight into a stage light or a low sun and you'll get veiling haze that washes the shadows. Use the hood. The 55mm filter thread is shared with a chunk of the OM prime line, so one set of polarizers and NDs covers your 50mm and this without a wallet of step rings.

Who reaches for it: portrait shooters who want compression and separation on a budget, documentary and candid people who need standoff distance, and anyone shooting available-light performance where you can't walk up to the subject. It is not a fashion-studio lens and nobody pretends it is. The honest weakness is that minimum focus is around 1.5 meters, so it's useless for tight detail or anything close. You're framing people and scenes, not flowers.

These go cheap today, which is most of the appeal. People cross-shop it against the f/3.5 version (slower, but more compact and a strong performer in its own right), and against the Nikkor and Canon FD 135s. Where the f/2.8 earns its slightly higher price is a dark room: that one stop is the difference between a shot and a smear in bar light. One metering habit worth keeping with an external meter: meter for the aperture you actually intend to shoot. If you want the f/2.8 look in dim light, set Zone Light Meter to f/2.8 so it solves for a usable shutter speed, and you'll keep the shadow detail this lens holds onto well.