Specifications : Lens Construction: 17 Elements in 13 Groups Angle of View: 94.5 - 56.8 degrees Number of Diaphragm Blades: 9 Blades Minimum Aperture: F22 Minimum Focusing Distance: 30cm / 11.8 in Maximum Magnification: 1:4.6 Filter Size: Diameter 82mm Dimensions: Diameter 89mm X Length 107.8mm3.5 in. x 4.2 in. Weight: 595g / 20.9 oz. Corresponding AF Mounts :Sigma, Canon, Nikon, Pentax, Konica-Minolta