Leica Summilux-M 21mm f/1.4 ASPH. is a premium ultra-wide-angle manual focus lens built for Leica M-mount rangefinder photographers who want exceptional low-light capability, dramatic perspective, and refined optical performance. Its fast f/1.4 aperture supports available-light shooting and shallow depth of field effects that are rare in this focal length, while the advanced optical design helps control distortion, vignetting, and chromatic aberration for high contrast and strong edge-to-edge clarity. With a floating element design, precise manual focus control, and Leica’s renowned mechanical construction, this lens is well suited for documentary work, environmental portraiture, architecture, and expressive wide-angle photography.