The Tamron 18-250mm lens features aperture range of f/3.5-22, seven-bladed diaphragm, 17.7" minimum focusing distance, and 13.8x zoom. The Di-II features is specially designed for cameras with APS-C image sensors. Encluded in this lens is a built-in motor to enable autofocusing with Nikon DSLR cameras equipping the lens, in conjunction with the camera, for faster and quieter focusing. Compact wide angles lens with Low Dispersion (LD) to improve image quaility, and one anomalous Dispersion lens element, and two hybrid aspherical lens elements. The Di-II design adds a gold color band between the focus ring and zoom ring to distinguish it from other designs.