This Nikon-mount version is the equivalent of a 21-31mm and features a new optical design with 13 elements in 11 groups, and a minimum focus distance of 0.9 ft (0.28m). Tokina paid special attention to reducing chromatic aberration with the addition of four ED-type elements, two of which feature aspherical surfaces. The lens also features a large-diameter plastic-hybrid molded asphere in the front group to improve sharpness and reduce spherical aberration.
With an 82mm-diameter accessory thread, and measuring 3.5 x 4.2” (89 x 106mm), the lens is a little larger than what we’ve become accustomed to in the PRO DX range.