Leica Summilux-M 75mm f/1.4

Walter Mandler built this one for himself, more or less. Asked in the early 1980s which of his designs he liked best, the man who drew the Noctilux f/1.0 and the 50mm Summilux pointed at the 75. He gave it as the balance between performance and size, which is a designer's way of saying he had nailed the compromise. Leica wanted a fast short telephoto for the M system, something that could throw a head-and-shoulders portrait clean off its background the way an SLR lens could, but do it on a rangefinder. Mandler took the high-index glass developed for the Noctilux and pushed a non-aspherical double-Gauss formula about as far as it would go: seven elements in five groups, first cut in Canada at the Midland plant, later in Germany. It stayed in the catalog until 2005, a run of about 25 years.

Wide open it does the thing you bought it for. Subject isolation at 75mm and f/1.4 on film is dramatic, the kind of falloff that makes a face float. The bokeh is the Mandler signature, smooth and rounded, with that faint Leica glow on highlights that some people chase and some people fix in post. But f/1.4 is not clinical. There is veiling softness across the frame, and you will see magenta and green fringing in the out-of-focus edges, especially against backlight. Stop to f/2.8 and the lens snaps into its real character: the focus plane gets bitingly sharp, contrast firms up, and the background is still liquid. That is the working aperture for portraits, and most owners shoot it there.

The honest weakness is focus shift. As you stop down, the plane of sharpest focus creeps backward, which on a rangefinder is a genuine problem because you focus wide open and shoot stopped down. At f/2 to f/2.8 with a thin depth of field, a small shift lands the sharpness behind the eyes. People learn to compensate by feel, or they shoot wide open where the rangefinder is calibrated, or they live with a slightly higher miss rate. It is the price of a fast non-aspherical design from 1980.

It is also heavy and front-loaded, around 560 grams of glass, and the 60mm filter thread is an odd size you will hunt for. None of that has dented its reputation. This is a portrait and low-light reportage lens, used by people who want the M form factor and a faster aperture than the lovely but tamer 75mm Summicron f/2 gives them. On the used market it runs in the low-to-mid four figures, and the modern cross-shop is the 75mm Noctilux f/1.25 ASPH at roughly three times the money and considerably more weight.

If you do work it at f/1.4 indoors, meter for the shadow you care about and let the highlights ride; the lens has plenty of glow to spare and a clipped catchlight reads worse than a lifted shadow. Zone Light Meter lets you place that shadow on the zone you want and read the wide-open exposure straight off, which matters when you are a stop or two from the meter's comfort zone and the depth of field is paper thin.