70 to 200mm Di fast zoom lens. The Tamron SP designation is reserved for lenses developed with special emphasis on extraordinary photographic performance. Engineers are free to innovate in an uncommon atmosphere where optical performance comes before price, resulting in lenses that satisfy the demands of discerning photographers. Tamron's SP 70 to 200mm F/2.8 Di LD (IF) Macro exemplifies the second of the two zoom focal lengths considered essential by many professionals. At just 7.6 inches long and weighing only 40.6oz, long days of shooting become easier and extraordinary optical design and exacting manufacturing assure the image quality that makes long shoots rewarding. A fast and constant F2.8 maximum aperture, renders cluttered backgrounds well out of focus, extends low-light shooting freedom and enables a brighter viewfinder image. Its IF (internal focus) mechanism maintains a fixed barrel length throughout the focusing range and superb optics, featuring LD (low dispersion) glass to assure remarkable image quality.