Leica Summicron 50mm f/2 (LTM, collapsible)

The lens that set the postwar standard for the normal Leica. It was designed at Leitz Wetzlar by Gustav Kleinberg and Otto Zimmermann, and it evolved from the Summitar that Max Berek had drawn in the late 1930s. Berek was the man who started the whole lineage, the optician behind the 50mm f/3.5 Elmar that put the early Leica on the map in the 1920s, but he died in 1949 and never saw this one finished. By the early 1950s Leitz needed something faster and sharper to answer the Zeiss competition and the looming arrival of the M3. The collapsible Summicron, introduced in 1953, was the answer: a seven-element double-Gauss built around the new lanthanum rare-earth crown glass formulated in the Leitz glass laboratory. It collapsed into the body so a IIIf with the lens mounted still slipped into a coat pocket. That was the whole point of the screwmount system, and this lens is its high-water mark.

What it renders is the reason people still chase clean copies. Wide open at f/2 it is sharp in the center to a degree that set a new benchmark for normal lenses of its day, with a soft falloff into the corners and a gentle veiling glow on highlights. Stop down to f/4 or f/5.6 and it sharpens across the frame while keeping the lower overall contrast typical of single-coated lenses of its era. That low contrast is what gives it the look. Blacks stay open rather than blocking up, midtones separate cleanly, and on black and white film you get long, smooth tonal transitions from shadow to highlight. Out-of-focus areas are smooth and unfussy. No swirl, no nervous edges, just a calm background that sits behind the subject without fighting it.

This is reportage and street glass first. It came up through the early Magnum generation and it does what that work needed. Small, quiet, fast enough to shoot indoors, and forgiving of imperfect focus. Portrait shooters love it for the same reason that disappoints the chart testers: the modest contrast keeps skin tones gradated instead of snapping them to hard edges, so faces hold their roundness.

The honest weakness is flare and coating. Single-coated front elements from the 1950s wash out and lose contrast badly against the light, and many surviving copies carry cleaning marks or the soft-glass haze that lanthanum elements are prone to. Shoot one into a window and you will see veiling that a modern multicoated lens would shrug off. Some people want exactly that effect. Most do not want it on every frame.

Where it sits now: a collector's lens that people actually use, cross-shopped against the rigid 1960s Summicron and the Canon 50mm f/1.8 LTM, which gives you most of the look for a fraction of the money. The collapsible commands a premium for the name and the rendering, and clean coated examples are not cheap. Buy the glass, not the box.

One practical note. Wide open in dim interiors is where this lens earns its keep, so meter for the shadows you care about rather than an averaged reading and let those single-coated highlights bloom. Zone Light Meter's spot reading lets you place a shadow on Zone III and trust the long midtone scale to carry the rest. The 39mm filter thread takes a yellow or orange filter cleanly for black and white work, and the lens is small enough that a screw-in filter never unbalances the camera.