The 85mm f/1.4 DG HSM Art Lens, and delivered an optic with high performance, a large f/1.4 aperture, and a variety of technologies. Available here with a Canon EF mount, this lens offers a super-fast f/1.4 aperture that is great for getting images with an exceptionally shallow depth of field and smooth bokeh. It also uses two SLD elements, one anomalous partial dispersion/high-refractive index element, and one aspherical element that minimize aberrations and ensures a crisp, clear image. A rounded 9-blade diaphragm also helps create round, smooth bokeh. It is made from a thermally stable composite material that is light and durable and it has a brass bayonet mount. Additionally, it is fully compatible with Sigma's USB Dock. This short telephoto 85mm f/1.4 prime lens is designed for full-frame format Canon EF-mount cameras, and can also be used with APS-C models where it will provide a 136mm equivalent focal length. Two SLD elements, one element with a high rate of anomalous partial dispersion and a high index of refraction, and one aspherical element have been incorporated within the lens design to correct for chromatic aberrations throughout the entire focusing range and help to ensure high image sharpness, clarity, and contrast regardless of focus point or aperture setting. This optical design also helps to control distortion and limit vignetting. 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. The lens is constructed using a Thermally Stable Composite (TSC) material, along with traditional metals, for greater precision and use in wide temperature variations.