Tamron SP AF17-50mm F/2.8 XR Di II LD Aspherical IF Now Available in Pentax Mount Lightweight, Compact, Fast 2.8 Standard Zoom Lens Designed for Exclusive Use with Digital SLR Cameras (APS-C Size), Featuring 17mm Wide-Angle
PMA, January 31, 2008, Las Vegas, NV-- Mr. Morio Ono, President of Tamron Co., Ltd., announced that Tamron has introduced its SP AF17-50mm F/2.8 XR Di-II LD Aspherical [IF] (Model A16) in Pentax mount designed exclusively for digital SLR cameras with smaller size image sensors.*
*Di (Digitally integrated)-II lenses are designed for exclusive use on
digital cameras with smaller-size imagers. This lens is not designed
for use with 35mm film cameras or digital SLR cameras with image
sensors larger than 24mm x 16mm.
The SP AF17-50mm F/2.8 XR Di II LD Aspherical [IF] has been well
received as a lightweight and compact, fast standard zoom lens. In
addition to Nikon, Canon and Sony AF mounts, it is now available in
Pentax mount to meet consumer demand.
MAIN FEATURES
1. Lightweight, Compact Fast Standard Zoom Lens is Designed Exclusively for Digital SLR Cameras, with 17mm Wide Angle Coverage
Exclusive design for digital SLR cameras achieves a fast standard zoom
lens that covers virtually the same angles as focal lengths of 26-78mm
when converted to a 35mm format. The wide-angle focal length is
established at 17mm (26mm equivalent) to obtain a wider angle of view
than ordinary standard zoom lenses, while maintaining the remarkably
lightweight and compact size of the earlier full frame zoom lens model.
Since the lens is designed exclusively for APS-C sized digital cameras,
the image circle diameter has been reduced. Moreover, careful
adjustments to the design have achieved a lightweight, compact body
with a filter diameter of 67mm, overall length of 81.7mm (3.2")*, and
weight of 434g (15.3oz.)*.
* Values given are for Nikon AF cameras.
2. Optical System Uses Special Glass, and Is Optimized for Digital SLR
Characteristics to Enhance Optical Quality in a Compact Design
The use of XR (Extra Refractive Index) glass in an innovative way
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 optical system. Furthermore, 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.
3. Minimum Focus Distance of 0.27m (10.6") over the Entire Zoom Range Affords a 1:4.5 Macro Capability
The new lens achieves a minimum focus distance of 0.27m (10.6") over
the entire zoom range, one of the best in its class among fast standard
zoom lenses with an F/2.8 maximum aperture throughout the entire zoom
range used exclusively for digital SLR cameras with APS-C sized image
sensors. The maximum magnification ratio of 1:4.5*1 at the 50mm setting
is the top level in its class.
*1 Since APS-C sized image sensors are smaller than 35mm film, the
17-50mm can fill the frame with almost the same scope as a lens with a
Max. Mag. Ratio of 1:3.0 on a 35mm SLR camera.
4. Optical Design Dedicated to Digital SLR Photography by Optimizing
the Angle of Incidence of Light Rays Reaching the Image Sensor
This zoom lens uses an optical system designed to confine the changing
angles of incidences of light rays reaching the imager within a certain
scope over the entire image field by considering the effects of
variance due to zooming.
5. 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.
6. Outstanding Resolution
Since the lens is designed exclusively for digital SLR photography, it
provides high image quality resolution, contrast and flatness of image
field.
7. 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 new 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 minimum.
8. Large Aperture in Lightweight, Compact Design Thanks to New Mechanical Devices
Complicated mechanisms are built into the compact body, thanks to new
mechanical devices, for excellent portability and ease of use. In
addition, a complex triple cam structure where cams zoom and focus
within a three-layer lens barrel has been further developed to improve
AF focus precision for close-in shots and torque irregularity when
zooming in and out. Additionally, the engineering of the lens has been
completely overhauled to downsize its parts and to increase their
precision and durability, in order to accommodate the complex structure
incorporated into the new SP AF17-50mm F/2.8 XR Di-II LD Aspherical
[IF].
9. Zoom Lock Mechanism Incorporated
The Zoom Lock prevents unwanted barrel extension when carrying the lens/camera combination.
10. Flower-Shaped Lens Hood
A glare-reducing flower-shaped lens hood is included as a standard
accessory. The special hood provides optimum shading of superfluous
light rays that enter from the rectangular frame outside the image
field.
11. New External Design of the New Di II Series Conveys "High Performance, High Precision Image"
Improvements have been made to the external design by adding a
gold-colored band between the focus and zoom rings to enhance the
appearance and make the product stand out as a Di-II lens. Also, the
black coating over the entire lens barrel creates a high-quality,
sophisticated look. The rubber patterns of the zoom rings have also
been improved to complement the digital camera design style and to
provide better handling.
Tamron SP AF17-50mm F/2.8 XR Di II. Courtesy of Tamron, with modifications by Zig Weidelich. Click here for a bigger picture!
Tamron SP AF17-50mm F/2.8 XR Di II Specifications
Model Name A16NII
Focal Length 17-50
Maximum Aperture F/2.8
Angle Of View 78°45' - 31 °11' (APS-C size equivalent)
Lens Construction 16 elements / 13 groups
MFD (Minimum Focus Distance) 10.6" (.27m) (over the entire zoom range)
Diaphragm Blades 7 (circular apertures)
Filter Size 67mm
Size (Diameter x Length) 2.9 in. x 3.3 in. (73.8mm x 83.7mm)
Weight 15.5 oz (440g)*
Max. Mag. Ratio 1:4.5 (at f=50mm, MFD 0.27m)
Minimum Aperture F/32
Standard Accessory Flower-Shaped lens hood
*Values given are for Nikon AF-D cameras. The cosmetic design and specs are subject to change without notice.
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