SP AF11-18mm F/4.5-5.6 Di II LD Aspherical [IF]
Model A013

An ultra-wideangle zoom lens providing reliable performance in a compact size for digital SLR photographers pursuing wideangle creativity

The lens uses a new optical system specially designed for digital SLR cameras, in addition to the use of a glass-molded aspherical element having a large clear aperture, hybrid aspherical elements, and elements using such special glass materials as high index/high dispersion glass and low dispersion optical glass, for outstanding optical performance.

FEATURE SUMMARY

Dedicated for digital SLR cameras
Through the employment of an optical design for exclusive use with digital (APS-C) SLR cameras, an ultra wideangle zoom lens with a focal length equivalent to a 17-28mm when converted to that of a 35mm full-size film camera lens has been realised. Using this lens along with the newly digital SLR-dedicated AF18-200mm zoom lens also introduced by Tamron, you can enjoy creative digital SLR photography with an astonishing choice of angles of view.

Features an optical system optimised for the characteristics of digital cameras
The optical system uses one element each of HID (High Index/High Dispersion glass) and LD (Low Dispersion) glass to minimise on-axis and lateral chromatic aberrations that are the greatest hindrance to high optical quality. In addition, the lens uses a high-precision, large clear aperture, glass-molded hybrid aspherical element and two hybrid aspherical elements to thoroughly compensate for spherical and chromatic aberrations and distortion, in order to achieve outstanding optical quality.

Optical design dedicated to digital SLR photography by optimising the angles of incidences of light rays reaching the imager
The zoom lens uses a new 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 from the centre to the periphery, by considering the effects of variances due to zooming.

Enhanced peripheral illumination
Peripheral light fall-off is minimised when compared with that of conventional lenses for film cameras so that images are uniformly bright from the centre to the periphery.

Outstanding resolution
Since the lens is designed exclusively for digital SLR photography, it provides high image quality in terms of resolution, contrast and flatness of image field.

Internal surface coating to reduce ghosting and flare
Ghosting and flare caused by aberrations are annoying factors in digital SLR photography, so Tamron has adopted various countermeasures to address the problem, including the employment of "Internal Surface Coatings" (i.e., multiple-layer coatings on cemented surfaces of plural elements) and new multiple-layer coating technology on ordinary elements. These minimise reflections that occur when light enters through the front element and also reduce image-degrading effects caused by the imagers themselves.

Flower-shaped lens hood
A glare-reducing flower-shaped lens hood is supplied as a standard accessory. The special hood provides optimum shading of superfluous light rays that enter from the rectangular frame outside the image field.

New external design conveys "high-performance, high-precision" image as one of the new Di-II series
Improvements have been made to the external design by adding a gold-coloured band above the focus ring to enhance the appearance and make it stand out as a Di-II lens. The rubber patterns of the zoom and focus control rings have been improved at the same time to complement the digital camera design style and to provide better handling.

SPECIFICATIONS

*Values given are for Nikon cameras.
**Nikon mount has a built-in AF motor.

NOMENCLATURE

Digitally Integrated Design for DSLRs with small sensors

Di II lenses are designed for exclusive use on digital SLR cameras with APS-C-format image sensors. All Di II lenses are optimised to meet the performance characteristics of DSLRs, providing maximal resolution concentrated within the image field and assuring that light rays at the edges of the frame reach the sensor at favourable angles, thereby minimising peripheral light falloff.

In addition, all Di II lenses incorporate effective measures to increase light transmission and eliminate ghosting and flare, which are particularly noticeable with digital cameras. Tamron’s advanced multi-coatings are applied not only to external and internal lens surfaces, but also to surfaces in between cemented lens elements. Finally, Di II lenses are offered in a wide array that includes the focal length ranges most desired by DSLR shooters.

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.

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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