Capture vibrant portrait shots with creamy out of focus background using the Sigma 40mm F1.4 Art DG HSM Lens. The lens can be used with Sigma SA mount cameras. This Sigma Art lens has an optical construction of 16 elements in 12 groups that include three FLD and three SLD elements to minimize chromatic aberrations and maintain edge-to-edge clarity. The Hyper Sonic Motor ensures noise-free autofocus down to a minimum distance of 15.7 inches. With the manual focus override function, you can accurately bring a subject into focus during the AF operation. The 9-blade electromagnetic diaphragm provides circular light iris in the out-of-focus parts to enhance the depth of field. Thanks to the maximum aperture of f/1.4, you don't have to increase the camera ISO to get clear images in low light. The lens barrel is dust- and splash-proof to ensure durability. An optional Sigma USB dock can be connected to the lens, which lets you adjust the focus settings and update the firmware.