The Sigma 30mm 1.4 DC DN Contemporary is a high performance prime with a large aperture of F1.4 designed for APS-C Mirrorless cameras including Sony E mount and Micro Four Thirds. The Contemporary line is part of Sigma Global Vision and is the perfect blend of image quality and compact size. The large aperture is great for lowlight and for creating depth of field and its small size makes it highly portable. A stepping motor provides fast and accurate autofocus and is highly useful for video work. Like all SGV lenses, each lens is hand crafted in our single factory in Aizu Japan, individually inspected before shipping. LENS CONSTRUCTION SPECIFICATIONS Lens Construction 9 Elements in 7 Groups Angle of View 50.7? Number of Diaphragm Blades 9 (Rounded) Minimum Aperture f16 Minimum Focusing Distance 11.8 in Filter Size (mm) 52mm Maximum Magnifications 1: 7 Dimensions(Diameter x Length) 2.6in x 2.9 in Weight 9.3 oz Corresponding Mounts Micro Four Thirds Sony E-mount