SP AF17-35mm F/2.8–4 XR Di LD Aspherical [IF]
Model A05  

Wideangle zoom lens with Di technology – ideal for use with both film and digital SLRs

This zoom lens covers a wide focal length of 17mm, considered ideal for digital SLRs. Their smaller formats and narrower angle of view than film-based SLRs make the wide focal lengths of typical wideangle zooms insufficient for many applications. Accordingly, there is an increasing demand for lenses with a wider angle of view. At the same time, these types of wideangle lenses are well accepted for use with conventional SLRs for their ability to add an interesting twist to photographic expression.

MAJOR FEATURES

Di technology guarantees high-quality digital images
Featuring Di (Digitally Integrated Design), the optical system designed to meet the performance characteristics of digital cameras, the lens lets you take high quality pictures with digital, as well as film-based 35mm format SLRs.

Attractive and useful focal length, 17-35mm
This lens provides a desirable wideangle focal length that is useful and fun for conventional SLR photography and acts as "wide-to-standard" zoom, equivalent to 25.5mm to 52.5mm on a Nikon DX-format SLR.

Consistent MOD of 30cm throughout the zoom range
With its maximum magnification ratio of 1:5.4 at the 35mm setting, this ultra-wideangle zoom enables creatively dramatic close-up shots, with a very near main subject emphasised and exaggerated against a wide background. The impressive MOD of only 30cm throughout the zoom range is the best in this class of lens.

Fast maximum aperture of f/2.8 at wideangle zoom
The maximum aperture of f/2.8 at the 17mm setting offers the advantage of shooting in dimly-lit conditions and helps to prevent the camera-shake that leads to blurred subjects. The fast aperture also allows more opportunity for selective focus, especially at the wideangle position, where depth of field is commonly deeper.

Aberrations corrected through the use of compound aspherical and LD elements
Image distortion, spherical, and other aberrations have been effectively corrected and eliminated through the use of three large compound aspherical elements, enabling high-definition photographs at any focal length. Moreover, colour anomalies such as chromatic aberration - characteristic of many wideangle lenses - have been diminished through the use of an LD element. This special glass compensates for lateral aberration, providing sharp and correctly coloured images even at the corners.

Maximum shading with supplied flower-shaped hood
The large-size flower-shaped hood, provided as standard accessory, is shaped to most efficiently and effectively cut flare from outside the lens' angle of view.

The form and texture of the lens indicate the SP* series' high performance and precision
The high-performance, precision "look" of this lens is fitting for the Tamron SP series. Finishing touches like the graphic display on the lens that features a more visible font, the finish of the lens barrel that utilizes a high quality, delicately wrinkled enamel that is not only durable but offers a comfortable feel, and more all add up to make a lens that handles and functions superbly in the field.

*SP: "Super Performance" - a line of high-performance lenses featuring high design specifications. In designing the SP series, the first and foremost priority is put on superior specifications and outstanding performance free from cost restraints. Therefore, SP lenses featuring impressive and innovative designs are concept models among Tamron lenses.

SPECIFICATIONS

NOMENCLATURE

Digitally Integrated Design

Di is a Tamron designation that applies to lenses that have been optimised for digital capture using advanced multi-coating techniques and optical designs that assure excellent image quality across the entire picture field. Because of these characteristics, Di lenses provide outstanding performance on cameras with full-frame and APS-C format sensors as well as on 35mm film.

Super Performance series

Tamron SP (Super Performance) series is a line of ultra-high-performance lenses designed and manufactured to the exacting specifications demanded by professionals and others who require the highest possible image quality. In creating SP lenses Tamron’s optical designers put their foremost priority on achieving superior performance parameters – they are all designed to a higher standard with little regard for cost constraints. As a result, Tamron lenses bearing the SP designation feature impressive and innovative designs that have established an enviable reputation for excellence among those knowledgeable photographers that demand the very best.

Extra Refractive Index

XR (Extra Refractive Index) glass can bend light rays at steeper angles, thereby decreasing the physical length of the lens while enhancing imaging performance by minimising optical aberrations. This has allowed Tamron to develop a line of shorter, smaller-diameter, lighter lenses without sacrificing lens speed, actually upgrading image quality compared to older designs.

XR glass is costlier than conventional glass but it yields enhanced optical power distribution, making possible many of the outstanding and innovative lens designs that bear the XR designation.

Low Dispersion

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. Although costly, LD glass materials result in clear, vivid image quality.

Aspherical

Tamron uses several hybrid aspherical lens elements in its lenses bearing the Aspherical designation. These innovative optics achieve the ultimate in image quality while producing lenses that offer remarkable zoom ranges in extraordinarily compact packages. These cutting-edge advances have advanced the state of optical design by virtually eliminating spherical aberration and image distortion from Tamron's high-power-zoom series.

As one hybrid aspherical lens element can take the place of multiple elements without compromising performance, remarkably compact long-range lenses can now deliver a uniformly high level of image quality across all focal lengths and apertures.

Internal Focusing

Tamron's internal focusing (IF) mechanism provides numerous practical benefits to photographers including:

• a non-rotating front filter ring that facilitates the positioning of polarising and graduated filters
• more predictable handling because the lens length does not change during focusing
• a much closer minimum focusing distance (MFD) 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.

Specifications, design, product name and standard accessories may differ by country or area. While every effort has been made to ensure accuracy, these matters are subject to change by the manufacturer without notice or obligation.

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