This large aperture standard zoom lens for use with both DSLR and 35mm film SLRs is constructed with 3 aspherical lens elements, 2 Special Low Dispersion elements to compensate for aberrations and Super Multi Layer Coating to reduce ghosting and flare. It has a minimum focusing distance of 40cm (15.7 inches). It uses a Dual Focus System for easy AF and has a focus ring for Manual. Because the front of the lens does not rotate, a petal-type hood and circularly polarizing filters can be used with ease.