Lens Leica APO-Summicron-SL 28mm f/2 ASPH, Leica L mount, black

APO-Summicron-SL 28 f/2 ASPH. is a combination of a classic wide-angle lens focal length and modern technologies. The viewing angle of the lens ensures maximum image capture without distortion of perspective as in indoor shooting conditions as well as during street photography. Focusing with a fully open aperture occurs across the entire field of the frame without loss of quality which gives the photographer much more opportunities to realize his creative ideas. The APO-Summicron-SL 28 f/2 ASPH does this. not just a universal lens but also with a lens contributing to the creation of the most extraordinary personnel.

Instant focus
The autofocus system of Summicron-SL series lenses is fast accurate and virtually silent. These lenses have outstanding autofocus performance , which are limited only by the total mass of the lens elements moving when focusing boundaries of possible focusing distances and, of course, available space for shooting. To maintain the compact dimensions of the lenses, the integration of all necessary components was carried out on the basis of an integrated approach. Optics specialists Mechanical and Electronics Engineering worked together as an interdisciplinary team to create a unique lens concept based on a dual internal focusing system. This system of two lightweight focusing lenses combines particularly compact drive elements. The choice of autofocus point is also determined based on the principle of dual autofocus. Before determining the correct direction of autofocus movement Several contrast measurements are taken at different focusing positions after which the most accurate focusing point is fixed. During this process, the focusing lenses move quickly back and forth possible thanks to the high-speed characteristics of the contrast autofocus system. Summicron-SL lenses feature extremely powerful and reliable stepper motors with the ability to use Dual Syncro Drive focusing ring mode;. Thanks to this, the focusing stroke is carried out in a fraction of a second making Summicron-SL lenses the best in class full frame camera optics in terms of speed and accuracy.

High contrast for greater depth of field
SL-Summicron lenses with a small aperture of f/2 are significantly more compact than many faster lenses but at the same time allow photographers to work with the same depth of field. This is possible due to contrast: the area with the highest contrast is perceived as sharp while less contrasting areas appear blurry. With SL-Summicron lenses this difference in contrast is significantly higher than other lenses: sharply focused objects come out with much more contrast than objects that are out of focus. It means that out-of-focus objects in the foreground or background appear less distinct and the subject is more clearly highlighted which creates a three-dimensional visual effect with very impressive apparent depth of field.

New standard. Optical and Mechanical

When developing Summicron-SL lenses, special attention was paid to preventing stray light and glare. Optical and mechanical design improvements were made through complex simulations prior to the first lens prototypes. As a result, inevitable glare is reduced to the highest possible level thanks to the high-quality coating of the lens surfaces.

Easy-to-use precision electronics
The SL-Summicron's focusing and iris functions are based on multiple control systems and mathematical modeling Because the dual focusing system places particularly high demands on the optics. Two autonomous focusing motors move synchronously and the positioning data is analyzed at a very high sampling rate before being transmitted to the camera. At the same time, communication with the camera occurs so quickly that there is no noticeable delay. This is what which makes the lens autofocus so fast and accurate. The diaphragm is driven by a stepper motor and a special micro-stepping control system ensures precise and fast movements with minimal vibration.

Manual focusing. New sensations
The SL-Summicron lenses take a completely new approach to the design of the manual focus ring: a ring magnet with north-south variable polarization is built directly into the ring. When the ring is rotated, the magnetic field changes its polarization the matrix monitors the magnetic field and sends data to the main processor. The lens is then moved to the appropriate focusing position based on the rotation angle and rotation speed. , which in turn provides even faster and more accurate manual focusing. This design of the manual focus ring guarantees reliable protection against dust and water splashes , provides shock resistance and protection from other mechanical loads and also prevents focusing inaccuracies due to temperature fluctuations. Even after many years of use, the manual focus ring of the SL-Summicron lens is impressively smooth and uniform..

Impressive down to the last detail
Consistently compact dimensions light weight The ergonomics and superior performance of the SL-Summicron lenses are impressive and thanks to the almost identical design of the lenses in the series, there is no need to get used to working with the manual focus ring again when changing lenses. The center of gravity of the lenses also remains virtually unchanged, which means that the camera always fits perfectly in the hand and shooting from a tripod becomes much more comfortable.

Design features
Features of the APO-Summicron-SL 28 f/2 ASPH. – optical system of 13 lenses manufactured using the latest technology and taking into account the centuries-old traditions of Leica. Three lenses with six aspherical surfaces correct monochromatic aberration and eight high-quality optical elements provide chromatic correction throughout the entire focusing range. Only thanks to the special optical property of lenses - anomalous partial dispersion chromatic aberrations can be compensated for with such perfection. As a consequence of this even light areas in the pictures are not subject to spurious coloration at sharp boundaries of contrasting objects.