The LEICA SUMMARIT-M 90mm f/2.5 is a versatile telephoto lens that offers outstanding optical and mechanical quality. Designed in an extremely compact and handy unit, it is ideal as a portrait lens that can also provide outstanding close-ups of landscapes or architectures and corresponds to a full-fledged 120mm telephoto lens when used on the LEICA M8.

Even at full aperture, this lens demonstrates excellent imaging capability with outstanding contrast over the entire image field. A slight reduction in quality can only be seen in the corners. With a lens configuration of five lens elements in four groups, distortion is very low and has very low dispersion overall. Maximum light falloff in the corners is around 1.6 f-stops at full aperture in the 35mm format. Stopping down to f/4 substantially reduces this light falloff at the periphery of the image.