Leica 11145 Camera Lens User Manual

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 negli-
gible 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 „oating 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 mo-
dels. 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 cushoin), 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 com-
mon 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 rst lens in the rear group helps to reduce spherical
aberration and atten the image eld. 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 „oating element“,
which is moved independently of the rest of the construction during focusing.
Summary: The Leica APO Summicron-M 1:2/50 mm ASPH. delivers exceptional picture quality and sets new standards in 35 mm
digital photography.
Optical design
Aspherical surface
Floating Element