As a moderate wide-angle prime, the APO-Summicron-SL 35 f/2 ASPH. is almost a universal lens. Its fast autofocus, robust design and construction and exceptional imaging quality make it an outstanding lens for reportage and a convincing choice for other areas of photography such as architecture, landscapes, portraiture and studio work. It is perfectly matched to the cutting-edge SL-System and has been conceived for long working life under professional shooting conditions.

• L-Mount Lens/Full-Frame Format
• Aperture Range: f/2 to f/22
• Five Aspherical Elements
• Multi-Layer and AquaDura Coatings
• Dual Syncro Drive Stepping AF Motor
• Dust and Moisture-Resistant Design

The AF system of the Summicron-SL lenses is fast, precise, and almost silent. They thank their outstanding AF performance figures to the autofocus drive unit they share. These are limited only by the mass of the lens elements moved when focusing, the travel from infinity to the closest focusing distance and, of course, the amount of space available. In order to preserve the compact dimensions of the lenses, the integration of these components must follow an integral approach.

With an initial aperture of f/2, the SL-Summicron lenses are significantly more compact than faster lenses, but still allow photographers to work with similar depth of field. The reason for this is contrast: the zone of highest contrast is perceived by viewers as being sharp, while zones with lower contrast are regarded as being unsharp.

In the construction of the Summicron-SL lenses, particular attention has been paid to the prevention of stray light and reflections. The optimization of the optical and mechanical design was carried out in elaborate simulations before the construction of the first prototype lenses. Unavoidable reflections are reduced to the best possible level by high-quality coating of lens surfaces.

The focusing and aperture setting functions of a SL-Summicron lens are based on a multitude of control systems and mathematical operations. The demands on the electronics are particularly high in the case of the double focusing system.

SL-Summicron Lenses feature a totally new manual focusing ring construction concept. In this concept, a ring magnet with alternating north-south magnetization is embedded in the manual focusing ring. The magnetic field changes its polarity when the ring is turned. A sensor monitors the status of the magnetic field and sends the data to the main processor. The drive then shifts the lens to the corresponding focusing position on the basis of the angle of rotation and the rotational speed.

The consistently compact dimensions, low weight, and the excellent grip and feel of the SL-Summicron lenses are particularly impressive when shooting. Thanks to the almost identical design of the Summicron-SL lenses, feeling for the MF ring is unnecessary after switching lenses and the center of gravity remains largely the same. This means that the camera always lies perfectly in the hand and makes working from a tripod much easier.