The FUJINON XF 16mm F2.8 R WR is designed to deliver exceptional resolution performance from Fujifilm's unique X-TRANS CMOS sensors through its precise optical design. Small and lightweight, the XF 16mm F2.8 R WR lens also adopts an inner focusing system driven by a stepping motor, which drives the lens' focusing elements into place through precise electrical pulses for extremely fast and auto-focusing capabilities. Metal components are used extensively on the exterior of the lens and the interior of the lens is sealed around the barrel in nine different locations to ensure its durability as well as the weather-resistance to its surrounding environments. Edge-to-edge sharpness from the center to the corners of the frame is achieved by the precise arrangement of 10 lens elements in 8 groups. This lens also includes two aspherical elements, which serve to suppress the image degrading effects of chromatic aberration and field curvature imperfection. Weighing in at 5.47oz (155g) and measuring just 1.79in (45.4mm) in length, this lens offers up the renowned image quality and refined style associated with the FUJINON XF family of lenses. With its metal exterior, precise click stops, and smooth dampening, this lens offers incredible image quality in a durable aesthetically pleasing appearance. The inner focusing AF system uses a stepping motor to move focusing elements into place through precise electrical pulses, in order to achieve fast and near-silent autofocus performance. The lens is designed to operate in temperatures as low as 14 Fahrenheit and is sealed at nine points around the barrel, making it both weather and dust resistant.