While overall dimensions are confined to the absolute minimum, the Tamron SP AF 70-200mm F/2.8 Di LD Macro Lens is packed with features that allow stress-free photography: a versatile minimum focus distance (MFD) of just 95cm over the entire zoom range; best-in-class maximum macro magnification ratio of 1:3.1 at f=200mm; an advantageous internal focusing (IF) system and, of course, the fast maximum aperture of f/2.8. The new tele-zoom lens covers a desirable focal length range of 70mm medium telephoto to 200mm telephoto when mounted on full-size format SLR cameras and a focal length range from 109mm to 310mm ultra telephoto when mounted on a DSLR camera with an APS-C sized imaging sensor.
Super Performance series
This Tamron SP AF 70-200mm F/2.8 Di LD Macro Lens is designed and manufactured to the exacting specifications demanded by professionals and others who require the highest possible image quality. The foremost priority is achieving superior performance parameters - high design standards take priority over cost constraints. As a result, Tamron SP lenses feature innovative designs that have established an enviable reputation for excellence amongst demanding photographers.
Chromatic aberration occurs when a lens element refracts different wavelengths of a ray of light - its rainbow colours - at very slightly different angles. This results in the 'colour fringing' that reduces the sharpness of an image. LD elements are made from special glass materials with extremely low dispersion indices (i.e. the refraction of a ray of light into rainbow colours is extremely narrow). Thus they effectively compensate for chromatic aberration at the centre of the field (on axis), a particular problem at long focal lengths (the telephoto end of the zoom range), and for lateral chromatic aberration (toward the edges of the field) that often occurs at short (wideangle) focal lengths.
In many lenses, the front elements move back and forth to alter the focus distance. With an internal focusing (IF) mechanism, the focusing elements are inside the optical design. Because the front lens elements remain static, the lens’ actual length does not change. This provides several benefits both to the image and during photography:
- The barrel is not subject to stray light entering from external helicoids that can adversely affect image quality
- A non-rotating front filter thread makes it easier to use filters such as graduated filters and polarisers
- A flower-shaped lens hood will remain in the correct position to most effectively shield the lens from stray light
- Better balance and more predictable handling because the lens length does not change during focusing
- Generally, a much closer minimum focusing distance throughout the zoom range
- Improved optical performance by minimising loss of illumination at the corners of the image field (vignetting)
- Suppression of other aberrations that become more troublesome at different focusing positions.
Integrated focus cam optimises internal focusing
Tamron's Integrated Focus Cam is a precision mechanical component that optimises the co-ordinated movement of the Internal Focusing (IF) system with the Multiple Cam Zoom Mechanism. This ingenious mechanism ensures accurate and seamless positioning of all the internal elements within the lens and coordinates them with the external zoom and focus controls.
|Lens Construction||18 elements in 13 groups|
|Angle of View ||Diagonal: 34°21'-12°21' |
|Minimum Focus Distance||0.95m throughout zoom range|
|Macro Magnification Ratio||1:3.1 (at f=200mm, MFD: 0.95m)|
|Weight||40.6oz (1150g) without tripod mount|
|Diameter x length||89.5 x 194.3mm|
|Supplied Accessories||Flower-shaped Lens Hood & case|
|Mounts Available||Canon, Pentax, Sony (Konica Minolta), Nikon AF-S (built-in AF motor)|