In order to combine outstanding wide-aperture, mid-telephoto performance with F1.4 brightness at maximum aperture, this lens incorporates 17 optical elements in 12 groups—an uncommonly large number of elements for a prime lens. By including three FLD glass elements, two SLD glass elements, and one aspherical lens element, the optical system minimizes axial chromatic aberration to deliver extremely high resolution along with ample peripheral light volume. The area in focus is extremely sharp, while the area out of focus features a beautiful bokeh effect with highly natural colors, making this lens a powerful choice for portrait photography. The optical system also minimizes sagittal coma are, making this lens excellent for capturing starry skies. The lens sports a Hyper Sonic Motor to produce quick, smooth, and quiet autofocus performance with full-time manual focus override. The physical design utilizes Thermally Stable Composite material for durability in a wide range of environments, and a brass bayonet mount also offers rigidity and mounting precision. For working atop a tripod, a removable tripod collar is also included and features an Arca-type compatible foot for wide mounting compatibility.The Sony E-mount version of this lens is compatible with Sony mirrorless cameras and contains the same optical system as the versions for other mounts. SIGMA MOUNT CONVERTER MC-11 is not required, as the lens performs the same functions as the converter, including in-camera image stabilization and in-camera lens aberration correction. In addition, the lens is compatible with Sony’s Continuous AF, which is not available via MOUNT CONVERTER MC-11. SIGMA plans eventually to offer Sony E-mount versions of every full-frame prime lens currently available in the Art line, from 14mm to 135mm.Main Features: