The new Leica APO-Summicron-M 50 mm f/2 ASPH. lens is yet more clear proof of Leica's leading role in optical excellence. With this new lens, Leica engineers have successfully expanded the limits of the technically possible to set new standards in imaging performance. It is the first lens ever to fully exploit the capabilities of modern high-resolution camera systems without any compromises.

This lens is a new milestone in the history of optical design that achieves previously unattainable values in all technical performance characteristics. For instance, there is practically no fall-off at the edges - even at full aperture - in the MTF curves for image sharpness. Even the finest details are rendered with more than 50% contrast - a previously unheard of value that confirms the exceptional properties of this lens.

This enormous contrast enables extremely sharp images with superb corner-to-corner detail rendition in all photographic situations. At the same time, the apochromatic correction of the lens minimises chromatic aberration on sharp edges to ensure natural rendition of every detail. This results in outstanding pictures - even in large-format prints. The Leica APO-Summicron-M 50 mm f/2 ASPH. provides discerning photographers with a new high-performance lens in the portfolio of standard focal lengths.

More than 30 years after the launch of Summicron-M 1:2/50 mm, which is still available, the Leica APO Summicron-M 1:2/50 mm ASPH. represents a totally new development. With its compact body - only marginally longer and slightly heavier than the Summicron-M 1:2/50 mm, and with an almost identical diameter, it provides visibly higher image quality. On the Leica APO Summicron-M 1:2/50 mm ASPH. the exceptional correction enables all aberrations to be reduced to a minimum level that is negligible in digital photography. Its key features include excellent contrast rendition, all the way to the corners of the image, even with a fully open aperture. The use of a "floating element" ensures that this is retained, even for close-up shots. Vignetting is limited to a maximum - i.e. in the corners of the image - of just 2 stops at full aperture in 35 mm format, or around 1 on the Leica M8 models.

Stopping down to 2.8 visibly reduces this light deterioration towards the edge of the image, with practically only the natural vignetting remaining. Distortion is very low at a maximum of just 0.4 % (pin cushion), which is practically imperceptible. A total of eight lens elements are used to achieve this exceptional performance. To realize the apochromatic correction (resulting in a common focusing plane for three light wavelengths), three are made of glass types with high anomalous partial color dispersion, while two of the others have a high refractive index. The aspherical surface of the first lens in the rear group helps to reduce spherical aberration and flatten the image field. While the optical construction in front of the aperture is a Gaussian type, the arrangement of the lens elements behind it is similar to that in the Summilux-M 1:1.4/35 mm ASPH. This group comprises a "floating element," which is moved independently of the rest of the construction during focusing.