The new Tokina AT-X 535 PRO DX lens (for Nikon) is a 50-135 with a fast constant aperture of f/2.8. This lens gives digital photographers the similar to the industry standard 80-210 telephoto zoom lens in 35mm camera terms but is much more compact and lightweight. The lens features SD glass lens elements to correct for chromatic aberrations and focuses all colors accurately at the film plane, making the AT-X 535 PRO DX an APO lens. The front element has a newly formulated WP or ?Water Proof? optical coating on the glass. This new coating makes marks such as spots left by water or finger-prints much easier to clean than standard multi-coating. Other features include a built-in tripod collar and One-touch focus clutch mechanism for fast switching between auto focus and manual focus modes. Specifications: Mount availability: Canon EOS, Nikon-D Focal length: 50 to 135mm Maximum aperture: f/2.8 Minimum aperture: f/32 Optical construction: 18 elements in 14 groups SD glass: One elements Coatings: Water Proof? optical coating Angle of view: 31? 3? ~ 11? 8? Minimum focus distance: 39.3 in. (1.0m) Reproduction ratio: 1:5.89 Zooming system: Rotary type Number of diaphragm blades: 9 Filter size: 67mm Maximum outer diameter: 3.07 in. (78.2mm) Dimensions: 3.07 in. (78.2mm) X L 5.32 in. (135.2mm) Weight: 29.8 oz. (845g) Lens Hood: BH-671