AT-X 14-20 F2 PRO DX is a wide-angle zoom lens with super-fast F2 aperture and designed for APS-C sensor DSLR cameras. In this short video we tried to explain main concept and advantages of the Tokina AT-X 14-20 F2 PRO DX as a zoomable lens that has an optical performance equivalent to prime lens. Due to all-new proprietary optical design that uses three aspherical lens elements (2 all-glass molded and 1 P-MO lens) AT-X 14-20 F2 PRO DX achieves superior contrast and sharpness, and corrects spherical aberrations. Additionally, Tokina uses four SD glass elements (Super-low Dispersion: FK01 and FK03) that control chromatic aberrations, distortion and astigmatism. Two of the elements are SD glass molded aspherical lenses that makes this lens especially exclusive.