The Tamron 200-500mm f/5-6.3 SP AF Di LD (IF) Lens for Canon EOS from Tamron is an ultra telephoto zoom lens designed to bring distant subjects close. Its minimum focus distance is 8.2' (2.5 m) and its maximum magnification ratio is 1:5 at 500mm. For a lens that covers such long focal lengths, it is relatively compact and lightweight. An internal focus system maintains its compact form as the lens does not extend when focusing. Its optical design consists of two Low Dispersion glass elements which minimize chromatic aberrations and provide sharp, high resolution, high contrast images. The lens is designated "Di" which stands for Digitally Integrated Design and meets the performance characteristics of digital and film SLR cameras. When mounted on a DSLR camera with an APS-C size sensor, it provides a focal length equivalent of 310-775mm. This lens features a detachable Filter Effect Control Ring. This allows a filter to be rotated to the desired position with the hood still attached, enabling you to easily perform minute adjustments to a polarizer filter. The lens also includes a dedicated lens hood to block stray light from entering the lens and causing flare and a detachable rotating tripod collar and mount to provide stability when shooting at long focal lengths.