Over a century of passion for photography is brought together in the new APO-Summicron-SL 50 f/2 ASPH. to create a new dimension of visual aesthetics. Its unique combination of highest detail rendition and a focal length that gets closest to what is naturally perceived by the human eye delivers especially ‘authentic’ results. Perfectly matched to the state-of-the-art SL-System, and with one of the fastest autofocus systems in the professional camera segment, the APO-Summicron-SL 50 f/2 ASPH. captures the essence of special moments in remarkable pictures. AF System with Dual Syncro Drive From zero to sharp in no time 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. Higher Contrast for greater perceived depth 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. Optically and Mechanically a new standard 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.