manual focusing in F/8.3-16 aperture at 420-800mm focal length, to separately control the super focal zoom from DSLR SLR cameras. Functional Structure:The lens consists of 4 elements in 2 groups, with lock to fix the lens for precise shoot. Whole metal structured body provides with tough and durable constructions. Ultra Multi Coating:Adopts multi-coated technology to reduce flare and ghost to get vivid color and clear images. Premium optical lens provides high light transmittance. T Mount Wide Compatibility:Powerful replacement accessories for Canon Nikon Sony Fujifilm Olympus cameras and more, adapter ring is needed for mounting. Universal 1/4 Mounting:The base with 1/4 screw thread down the lens makes wide application on tripod and monopod, the base with ring can rotate, convenient to install in seconds. Specifications:Color: Black/ White(optional) Material: Metal Mount: T mount Replacement for: Canon Nikon Sony Fujifilm Olympus cameras and more DSLR and SLR cameras (Adapter ring needed, Not included) Focal Length: 420-800mm zoom lens Aperture: f/8.3@420mm-f/16@800mm Optical Constructions: 4 elements in 2 groups Zoom System: Linear push-pull Exposure: Automatic exposure is available in Aperture Priority mode only for cameras with TTL metering systems; Other camera must be set in full manual Focusing: Manual helical(rotary) operation(Not AF compatible) Minimum Focusing Distance: 1.6 meters(5.25ft) from front lens element Filter Size: 62mm Diameter: 69mm Length: 24-35cm / 9.45-13.38in(with caps) Lens Dimension: 24 * 7 * 7cm / 9.45 * 2.76 * 2.76in Weight: 659g / 18.3oz Packing List: 1 * MF Super Telephoto Zoom Lens 1 * Front Cap 1 * Rear Cap 1 * Carrying Pouch