Leica APO-Summicron-M 50 mm f2.0 ASPH Plata

Description

More than 30 years after the launch of the Summicron-M 1:2/50 mm, which is still available today, the Leica APO Summicron-M 1:2/50 mm ASPH represents a completely new development. With its compact body—only slightly longer and slightly heavier than the Summicron-M 1:2/50 mm—and with an almost identical diameter, it delivers visibly higher image quality.

In the Leica APO Summicron-M 1:2/50 mm ASPH, the exceptional correction allows all aberrations to be reduced to a minimum level, which is insignificant in digital photography. Its key features include excellent contrast reproduction, right up to the corners of the image, even with a wide-open aperture. The use of a "floating element" ensures this is maintained, even for close-ups.

Vignetting is limited to a maximum—i.e., at the corners of the image—of just 2 stops at full aperture in 35mm format, or around 1 on the Leica M8 models. Stopping down to 2.8 stops visibly reduces this light deterioration toward the edge of the image, with virtually no natural vignetting remaining.

Distortion is very low, at a maximum of 0.4% (pincushion), which is practically imperceptible. A total of eight lens elements are used to achieve this exceptional performance.

To perform apochromatic correction (resulting in a common plane of focus for three wavelengths of light), three lenses are made from 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 reduce spherical aberration and flatten the image field. While the optical structure in front of the aperture is Gaussian, the arrangement of lens elements behind it is similar to that of the Summilux-M 1: 1.4/35mm ASPH. This group comprises a "floating element," which moves independently of the rest of the structure during focusing.