***This lens is fitted with a seamless lens gear for use with follow focus applications***This short telephoto 85mm f/1.4 prime lens is designed for full-frame Sony E-mount mirrorless cameras, and can also be used with APS-C models where it will provide a 127.5mm equivalent focal length.Sigma looked to create a peak portrait prime with the 85mm f/1.4 DG HSM Art Lens, and they delivered an optic with high performance, a large f/1.4 aperture, and a variety of technologies. Available here with a Sony E 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 Super Multi-Layer coating helps by suppressing flare and ghosting.For operation, a Hyper Sonic AF motor provides fast, accurate focusing and a large focusing ring permits manual focus override for making fine adjustments. 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.