The Tamron AF 28-200mm Super Zoom f/3.8-5.6 XR Di Aspherical IF Macro Lens is a very compact and lightweight zoom lens with a constant 1.6' minimum focus distance and a maximum magnification of 1:4. The remarkable achievements are brought about through XR (extra refractive index) glass.
This highly popular lens has now been improved with the Di optical system, with improved multi-coating for digital SLR cameras as well as film cameras, further enhancing its ease of use and popularity.
Approximate focal lengths when used with 35mm cameras and their equivalent angle of view when used with APS-C sized digital camera sensors: 28mm = approx 43mm; 50mm = approx 78mm; 100mm = approx 155mm and 200mm = approx 310mm.
Note:
AF not supported by D40 and D60 cameras.
Di Design
Digitally Integrated is a designation Tamron puts on lenses featuring optical systems designed to meet the performance characteristics of digital SLR cameras. By employing "Internal Surface Coatings" and multiple-layer coating technology on ordinary elements, ghosting and flare due to reflections that occur when light enters through the front element and reflections caused by the imagers themselves are reduced to the absolute minimum.
XR Design
Features XR (extra refractive index) glass and efficient use of aspherical lenses.
Zoom Range
A 7x magnification power is now available when used with digital SLR cameras. The focal length of when used on digital SLRs is equivalent to approx. 45-320mm in 35mm format (depending on camera brand).
IF System
Incorporates an Inner Focusing system and features a non-rotating front lens barrel for convenient filter use.