The Tamron 70-200mm f/2.8 Di LD (IF) Macro Lens is a telephoto zoom lens that has a large maximum aperture of f/2.8 which remains constant throughout the zoom range. It also offers an excellent “close-focusing-distance” minimum of just 3.1′ (0.95 m) throughout its entire zoom range, with a maximum macro magnification ratio of 1:3.1 at f=200mm. When mounted on an APS-C sensor size digital SLR camera, it provides a focal length equivalent of 112-320mm.
Di (Digitally Integrated Design) is a designation Tamron puts on lenses featuring optical systems designed to meet the performance characteristics of digital SLR cameras. Features like LD glass elements and Internal Focusing put this lens in the same category as the much bigger and more expensive professional Tamron lenses.
Two LD glass elements reduce various aberrations while minimizing the fall-off of light at the corners
The lens neither extends nor contracts physically when focusing; all moving elements are contained within the lens barrel
Digitally Integrated (DI) design lenses are designed to meet the performance characteristics of digital SLR cameras
The SP AF 70-200mm F2.8 Di LD (IF) Macro is certainly a very creditable effort by Tamron to produce a high quality, yet affordable fast telephoto zoom. Indeed if we look solely at the studio optical tests, it is a resounding success, as the technical quality of the images this lens can produce is superb throughout most of the range, matching or even outperforming the much more expensive Canon 70-200mm F2.8 L IS USM.
The Tamron 70-200mm f/2.8 Di Macro Lens delivers sharp images from a great focal length range and a wide/fast aperture in an economical package. The autofocus system is the clear downside to this lens.
The build quality is on a high level but it does not reach Canon L level here. The main weakness of the lens is its conventional AF. It is not all that bad when using phase-detection AF but it is far from being a speed demon. Contrast AF is downright miserable and manual focusing is cumbersome.