The Leica APO-Summicron-M 50mm f/2.0 ASPH Lens sets a high bar for performance: looking at the MTF chart, at an aperture of f/5.6 the lines for both tangential and sagittal structures are absolutely flat. This means that there this is zero image degradation. Even the finest details are resolved with greater than 50% contrast across the entirety of the image field. Vignetting is restricted to just 2 stops at full aperture in 35mm format, equivalent to about 1 on Leicas M8 models, and stopping down to f/2.8 visibly minimizes this light deterioration towards the images edges, with virtually none but the natural vignetting remaining. To achieve this high standard the lens features eight lens elements and apochromatic correction to minimize chromatic aberration along sharp edges. To realize the stunning apochromatic correction, it was necessary to utilize specially-formulated glasses based upon original creations of the former Leitz glass lab. Constructed completely by hand in Germany, and composed of only the best materials, the APO-Summicron-M 50mm f/2.0 ASPH Lens is a testament to the amazing achievements that are possible when advanced technology, vast knowledge, and meticulous, expert craftsmanship collide. Like all M-mount lenses, this 50mm f/2 features a manual focus design, and a convenient focusing tab for more refined control during use.