The Canon EF 35mm f/1.4 DG HSM Art Lens from Sigma mixes a comfortable focal length with an especially fast design. The bright f/1.4 maximum aperture helps to achieve shallow depth of field and selective focus effects and also suits working in difficult lighting conditions. The optical layout incorporates both low dispersion and aspherical elements, which help to improve sharpness and clarity by controlling both spherical and chromatic aberrations. A floating elements system is also used to maintain performance throughout the focusing range. The physical design features a brass bayonet mount, which offers rigidity and mounting precision along with a seal to guard against dust and moisture. Additionally, a rounded nine-blade diaphragm contributes to a pleasing bokeh quality. Wide-angle prime is designed for full-frame Canon EF-mount cameras, however, is also suitable for APS-C models where it provides a 56mm equivalent focal length. One F Low Dispersion (FLD) element and four Special Low Dispersion (SLD) elements are featured in the optical design and help to reduce color fringing and chromatic aberrations for improved clarity and color accuracy. The floating elements system helps to realize consistent optical performance throughout the focusing range, from 11.8" to infinity. The integrated HSM (Hyper Sonic Motor) realizes quick and quiet autofocusing, which is further complemented by an optimized AF algorithm to produce smoother focusing performance. The HSM also permits full-time manual focus control simply by rotating the focus ring at any time. This lens is compatible with the optional Sigma USB Dock for fine-tuning different lens characteristics and updating its firmware.