The Tamron SP AF17-50mm f/2.8 XR Di II LD Aspherical [IF] is a
lightweight, compact, fast standard zoom lens designed exclusively for
digital SLR cameras. The focal length of this lens is equivalent to
approx. 26-78mm in 35mm format.
This lens offers an f/2.8 maximum aperture throughout the entire zoom
range, to ensure stress-free photographic shots at all focal lengths and
distances. Additionally, a broader photographic expression through the
use of faster shutter speeds as a result of the maximum aperture offers
enhanced photographic pleasure.
Note: Di-II lenses cannot be used with digital SLR cameras using image
sensors that are larger than that of an APS-C size imager, or with 35mm
film SLR cameras.
Optimized for Digital SLR
The use of XR (Extra Refractive Index) glass optimizes the overall
distribution of optical power, and also reduces various aberrations to
the absolute minimum while achieving remarkable compactness. In
addition, suitable positioning of two hybrid aspherical elements serves
to maintain imaging performance and to shorten and compress the entire
An LD (Low Dispersion) glass element is used to accomplish effective
compensation of on-axis and lateral chromatic aberrations, a critical
factor for enhancing optical quality in digital photography, in order to
achieve outstanding optical performance over the entire zoom range.
Enhanced Peripheral Illumination
Peripheral light fall-off is minimized when compared with that of
conventional lenses for film cameras, so images are uniformly bright
from the center to the periphery.
Internal Surface Coating to Reduce Ghosting and Flare
By employing "Internal Surface Coatings" (i.e., multiple-layer coatings
on cemented surfaces of plural elements) and multiple-layer coating
technology on ordinary elements, ghosting and flare due to the
reflections that occur when light enters through the front element and
reflections caused by the imagers themselves are reduced to the absolute
Zoom Lock Mechanism
The Zoom Lock prevents unwanted barrel extension when carrying the