The Tamron AF 28-75mm f/2.8 XR Di LD Aspherical (IF) Macro Zoom is a fast and versatile lens. "Di" (Digitally Integrated Design) is a designation Tamron puts on lenses featuring optical systems designed to meet the performance characteristics of digital SLR cameras. It delivers high performance across the zoom range and the macro has a minimum focusing distance of 13" and a maximum magnification ration of 1:3.9 (at 75mm). LD glass elements reduces various aberrations while minimizing the fall-off of light at the cornersFeatures XR (extra refractive index) glass and efficient use of aspherical