APO-SUMMICRON-SL 1:2/35 ASPH.

Motives in Context

As a slightly wide-angle standard focal length, the application possibilities of the APO-Summicron-SL 1:2/35 ASPH. are almost unlimited. With its fast autofocus, robust design and outstanding image quality, it is ideal for reportage photography, but also impresses in other areas such as architecture, landscape and portrait photography as well as in studio use. It is perfectly adapted to the modern SL system and was developed for a long service life under professional conditions.
 

AF system with
Dual Syncro Drive™
From 0 to sharp in a fraction of a second

The autofocus of the SL-Summicron lenses is fast, precise and quiet. The drive unit determines the performance of the AF. This is limited by the weight of the focus lenses, the travel from infinity to close-up and of course the available space. In order to maintain the compactness of the lenses, these components must be integrated in a holistic approach.

An interdisciplinary team of optics, mechanics and electronics developers has developed a unique lens concept based on double internal focusing. This system, which consists of two particularly light focus lenses, allows the use of small and compact drive systems. In addition to the spatial restrictions, the selection of drive motors is also determined by the AF principle.

In order to determine the correct focus direction and then focus precisely, several contrast measurements are necessary at different focus positions. To do this, the focus lenses must be moved quickly back and forth according to the speed specifications of the contrast AF system. This requires a dynamic drive with no play.

The SL-Summicron lenses use extremely powerful and robust stepper motors with Dual Syncro Drive™. These can cover the entire focusing range in just a few fractions of a second. This means that the SL-Summicron lenses achieve the best values ​​in terms of speed, precision and noise emissions among full-format systems.

 

More contrast
for more depth effect

With an aperture ratio of 1:2, the SL-Summicron lenses are much more compact than even more light-sensitive lenses, but allow you to work with a similar depth of field. The reason for this is the contrast: the viewer perceives the zone of the highest contrast as sharp, while the area with a lower contrast in comparison is seen as blurred.

With SL-Summicron lenses, this contrast difference is much greater than with conventional lenses: focused objects have a higher contrast than unfocused ones. This means that objects stand out more from the foreground or background. The subject can be separated better. The result is a three-dimensional image impression with a very impressive depth effect.
 

Optically and mechanically
a new standard

When designing the SL-Summicron lenses, particular attention was paid to avoiding stray light and reflections. The optical and mechanical design is optimized before prototypes are built using complex simulations and highly effective lens coatings. Unavoidable reflections are reduced to the best possible level by high-quality coating of the optical surfaces.
 

Complex Electronics
for uncomplicated handling

Focusing and aperture setting of an SL-Summicron lens are based on a large number of controls and calculations. Double focusing in particular places high demands on the electronics.

The two autonomous focusing units must be moved absolutely synchronously and the position data must be evaluated at a very high frequency and passed on to the camera. Communication with the camera takes place so quickly that there is no noticeable delay. These are basic requirements for fast and precise contrast autofocus.

The aperture is driven by a stepper motor. A special control in microsteps ensures precise, fast, quiet and low-vibration movement.

 

Manual focusing
experience anew

 

SL-Summicron lenses use a new design of the manual focus ring. A ring magnet with alternating north pole and south pole magnetization is embedded in this. When the ring is rotated, the magnetic field changes. A sensor evaluates the magnetic field and sends its measurement signals to the main processor. The focus position is moved accordingly depending on the angle of rotation and the speed of rotation.

The design of the MF ring guarantees reliable sealing against splashes of water and dust, protects it against impacts and other mechanical stresses and prevents temperature fluctuations from affecting the focusing. Even after years of use, the MF ring of an SL-Summicron lens is characterized by play-free operation and uniform focusing.

Convincing
down to the smallest detail

In use, the SL-Summicron lenses impress with their uniform compactness, low weight and excellent feel.

Thanks to the almost identical design of the SL-Summicron lenses, there is no need to feel for the MF ring again after changing lenses and the center of gravity remains largely the same. This means that the camera always fits perfectly in your hand and handling on a tripod is also made easier.