Leica Tele-Elmar-M 135mm f/4

Stop this lens down to f/5.6 and the resolution holds dead flat across the frame, corner to corner, which is exactly what the 1965 redesign was after. The earlier Elmar 135mm f/4 was a longer four-element design. The Tele-Elmar that replaced it used a genuine telephoto formula, so the physical barrel sits shorter than the focal length. Five elements, and it stayed essentially unchanged for over three decades. When Leica finally revised it into the Tele-Elmar-M in the 1990s the optics carried straight over, because there was nothing to fix. The tradeoff was weight: the older Elmar is the lighter lens, and the more compact Tele-Elmar is actually noticeably heavier in its all-metal barrel.

Wide open at f/4 it is already sharp, sharper than most people expect from a lens this old, with only a faint drop in contrast that clears the moment you stop down a third of a stop. The bokeh stays quiet rather than expressive. Out-of-focus highlights hold their round shape, the background dissolves without fuss, and that restraint is exactly why faces and architecture come through so cleanly. Color is neutral. Flare resistance is excellent for a single-coated design, helped by the recessed front element, and visible distortion is close to nil.

The honest problem is the rangefinder itself. 135mm is the longest focal length the M coupling can reliably focus, and at f/4 your margin for a missed patch is thin. The frameline sits small and crowded into the corner of the finder. Plenty of people who love this lens on paper still struggle to nail focus on a moving subject at full aperture, which is why some shooters reach for the 1.25x or 1.4x viewfinder magnifier, and others simply learn to live at f/5.6 and beyond. On a body with a worn or slightly decalibrated rangefinder, this is the lens that exposes the flaw first.

It lives in the used market now as a quiet bargain. Set against the modern APO-Telyt-M 135mm f/3.4, which resolves higher and costs several times as much, the Tele-Elmar is the value 135 for anyone not chasing the last increment of correction. Portrait shooters who want compression without an SLR tele on their shoulder reach for it. So do landscape photographers picking detail out of a far hillside, where stopped-down performance is all that matters and focus can be leisurely. With a 39mm filter thread you can screw in an ND or a polarizer for that distant-haze work, and when you do, Zone Light Meter folds the filter factor into the exposure so a long lens does not quietly underexpose your skies.

It has been in production, in one form or another, since 1965, and the design has held up because it was right the first time. Small, all metal, sharp at full aperture, and forgiving of nothing about your rangefinder. Keep that calibration honest and it will outshoot lenses costing five times the money.