The APO-Summicron-SL 75mm f/2 ASPH. lens from Leica is a short telephoto prime designed for full-frame L-mount mirrorless cameras, however it can also be used with APS-C models where it will provide a 112.5mm equivalent focal length. Featuring a bright maximum aperture of f/2, it is well-suited to working in low-light conditions and with shallow depth of field techniques. The apochromatic optical design uses anomalous partial dispersion glass to reduce chromatic aberrations throughout the aperture range for improved colour and clarity, and one aspherical element is also used to reduce distortion and spherical aberrations for improved sharpness. Additionally, multi-layer coatings have been applied to limit surface reflections, flare and ghosting for increased contrast when working in strong lighting conditions. The lens is completed with a Dual Syncro Drive stepping motor for fast and quiet autofocus performance, and full-time manual focus override is available for more fine-tuned focusing control. A floating elements system and an internal focusing design ensures consistent imaging quality throughout the focusing range, from 1.6 to infinity. A water-repellent AquaDura coating has also been applied to the exposed front and rear elements to protect against moisture, and weather-seals have been incorporated in the lens design to benefit working in harsh environmental conditions.
