As part of the Art line within Sigma’s Global Vision series, this lens is designed to achieve truly notable optical performance and is ideally suited for creative and artistic applications.Standard zoom is designed for full-frame Leica L-mount mirrorless cameras, however can also be used with APS-C-format models where it will provide a 36-105mm equivalent focal length range.Constant f/2.8 maximum aperture is well-suited for working in available light conditions and also provides greater control over depth of field when using shallow depth of field techniques.Six F Low Dispersion (FLD) and two Special Low Dispersion (SLD) elements markedly reduce chromatic aberrations and colour fringing throughout the zoom range for improved clarity and colour accuracy.Three aspherical elements control spherical aberrations and distortion for increased sharpness and accurate rendering.Both Super Multi-Layer and Nano Porous Coatings have been applied to lens elements in order to minimise lens flare and ghosting and contribute to producing contrast-rich and colour-neutral imagery, even in backlit conditions.Integrated stepping motor realises quick and quiet autofocus, which is further complemented by an optimised AF algorithm to produce smoother focusing performance.At the wide-angle end of the zoom range, a minimum focusing distance of 7.1″ is possible with a maximum magnification of 1:2.9 to suit working with close-up subjects. At the telephoto end, the minimum focusing distance is 1.25′ with a maximum magnification of 1:4.5.Integrated AF-L button can be programmed to adjust various shooting settings and the lens also features a dedicated AF/MF switch and a zoom lock switch to prevent the barrel from accidentally extended.Rounded 11-blade diaphragm contributes to a pleasing bokeh quality.Brass bayonet affords improved mounting accuracy and rigidity and rubber sealing is incorporated in the mount’s design to render it dust- and splash-resistant.