The Tokina 24-70mm F2.8 PRO FX lens is a standard wide-angle to moderate telephoto lens featuring a bright, constant f/2.8 maximum aperture. Designed for full frame Canon and Nikon camera bodies, this everyday lens is ideally suited for nearly any genre of photography, including travel, portraiture, landscape, and event shooting.The new groundbreaking proprietary optical design uses three precision moulded all-glass aspherical lens elements to achieve excellent contrast, sharpness, and corrects for spherical aberrations. One of these elements is made from Super-Low Dispersion (SD) glass and it is a large sized aspherical element. These lens elements also yield even illumination across the whole image sensor.The Tokina 24-70MM lens also uses three SD (super-low Dispersion, “FK01” and FK03”) glass elements in the rear groups to control chromatic aberrations. The fast constant F2.8 aperture makes viewing and auto focusing possible in very low light situations while keeping some flexibility for setting the shutter speed. In addition to excellent optics, the lens incorporates a fast moving SDM (Silent Drive-Module) motor to greatly reduce AF noise making it one of Tokina’s quickest and quietest auto-focusing lenses to date. Tokina’s exclusive One-touch Focus Clutch Mechanism allows the photographer to switch between AF and MF simply by snapping the focus ring forward for AF and back toward the lens mount for manual focusing. The lens is also designed to stand up to the rigors of daily use by photographers in a wide variety of shooting conditions and environments. Specifications Focus distance: 24 - 70 mm Max aperture: F2.8Minimum aperture: F22 Lens configuration: 15 elements in 11 group Coating: Multilayer coating Angle of view: 84.20° - 34.49° Filter size: 82mm Shortest Object Distance: 38 cm Aperture blades: 9 Dimension: 89.6 x 107.5 mmWeight: 1010 g Hood (Attached) : BH-822