Tamron AF18-270mm F/3.5-6.3 Di II Lens

A technological breakthrough – the world’s longest range 15x zoom DSLR lens has exclusive built-in Vibration Compensation mechanism optimised for consumer digital SLR cameras

The Tamron Model B003 is the first digital SLR lens in the world to deliver a remarkable zoom ratio of 15x (28-419mm equivalent) while also featuring a highly effective Vibration Compensation (VC) system for clearer images. Designed exclusively for digital SLR cameras with APS-C sized image sensors, the new Tamron lens delivers outstanding image quality over its entire zoom range and its exclusive VC anti-shake system facilitates sharp and clear handheld photography even at the longest telephoto settings.

With its vast zoom range, the Tamron AF18-270mm F/3.5-6.3 Di II VC lens enables the user to cover virtually any photographic subject from wide angle to ultra telephoto, simply by zooming the lens to the required position. It covers angles of view equivalent to 28mm to 419mm when converted to 35mm film format. In addition, this breakthrough lens is equipped with Tamron’s exclusive, proprietary tri-axial Vibration Compensation (VC) mechanism, eliminating or substantially reducing the effects of handheld camera shake. As a result, the user can enjoy the convenience of handheld photography in virtually any situation, from shooting candid images, to covering sporting events, to news photography, without worrying about camera shake having an adverse effect on image quality.

Note: Di II (Digitally integrated) lenses employ optical systems designed for exclusive use on digital SLR cameras equipped with smaller sized (APS-C sized) image sensors. Di II lenses are not designed for use with 35mm film cameras or digital SLR cameras with image sensors larger than 24mm x 16mm.

DEVELOPMENT BACKGROUND

Since launching the Tamron AF28-200mm F/3.8-5.6 (Model 71D) in 1992 – a lens highly acclaimed as the first high power SLR zoom lens suitable for practical use – Tamron has continued to develop innovative zoom lenses as the "pioneer in high power zoom lenses". With the AF18-200mm F/3.5-6.3 XI Di II (Model A14), Tamron achieved an 11.1x zoom power for the first time in a zoom lens exclusively designed for digital SLR cameras. Tamron developed telephoto range further to 13.9x with the AF18-250mm F/3.5-6.3 Di II (Model A18), a lens that has gained wide popularity for its all-in-one capability for those photographers seeking light weight, small size but broad capability in multiple shooting situations.

The Tamron AF18-270mm Di II VC enables the user to cover an extremely wide angle-of-view range equivalent to a 28mm-419mm lens in the 35mm format. Tamron’s exclusive VC capability provides maximum compensation performance at all focal lengths and corrects shake so effectively that up to 4x slower shutter speeds can be used without loss of image sharpness. The VC system enables the user to enjoy the full benefits of ultra-tele photography comfortably. By providing remarkably stable viewfinder images as well, framing the shot has never been simpler at extreme telephoto lengths. In short, this unique VC image stabilisation system delivers the maximum potential built into the world’s longest-ratio zoom lens – 15x.

Tamron’s commitment to ongoing research and development is evidenced by continued breakthroughs in its traditional goals of lightness and compactness. The Tamron AF18-270mm Di II VC delivers all the functionality and performance you expect from a Tamron ultra high-power zoom, exemplifying the concept of "One great lens covering everything from wide angle to telephoto".

MAIN FEATURES

World’s first and greatest zoom ratio of 15x, covering a 28-419mm 35mm-equivalent angle of view

Going back to the basic concept of “one lens covering everything from wide angle to telephoto,” engineers at Tamron took up the difficult task of expanding the zoom range of their high power zoom lenses even further. Their unstinting efforts to extend the telephoto end beyond previous limits, while also retaining the wide-angle end at 18mm, has borne fruit as an ultra high power zoom lens that is exclusively designed for DSLR cameras and boasts the largest zoom range, at 15x, for the first time in the world.

Tamron’s original VC mechanism for effective shake-free hand-held photography: how the system works

Tamron’s proprietary VC (Vibration Compensation) mechanism was first seen in the AF28-300mm F/3.5-6.3 Di VC. Its powerful compensation effect employs a tri-axial system designed to let three coils drive a compensator lens electromagnetically via three steel balls. Since the compensator lens is supported on rolling steel balls with very low friction, follow-up performance is also enhanced, resulting in stabilised viewfinder images. Since the mechanism is designed to allow parallel shifting of the compensator lens solely by means of electrical control, the mechanical construction is simpler and more compact, resulting in the smallest, lightest DSLR lens possible.

Designing a high-power, compact zoom lens with VC mechanism: optical design optimisation meets optimum power distribution

In developing such a long-range zoom lens, Tamron’s optical designers pursued the optimum distribution of power within the overall optical system, which uses two LD (Low Dispersion) glass elements and three aspherical elements in order to effectively compensate for various optical aberrations, such as astigmatism. Yet this design allows the first optical group to be small enough in diameter to achieve the overall goal of a compact lens that also incorporates a handheld-shake compensation mechanism.

Note: In order to achieve such a high 15x zoom ratio, the optical system does not employ XR (extra dispersion) glass elements. Instead, compactness is achieved through optimisation of the power distribution within the whole optical system.

Minimum focusing distance of 0.49m over the entire zoom range for the maximum magnification ratio of 1:3.5

The lens allows close focusing down to 0.49m (20 inches) from the subject over the entire zoom range, even though it also includes VC capability. The maximum magnification ratio of 1:3.5 at its 270mm telephoto end results in class-leading capability in high-power zoom lenses designed for digital SLR cameras.

Optical system optimised for digital SLR cameras by taking incident rays of light reaching the image sensor into consideration

To effectively compensate for changes in light patterns entering the lens while zooming, the innovative optical system in this zoom lens is designed to converge the angles of rays of light entering from the centre to the periphery of the lens. The light rays thus reach the image sensor within a defined circle that assures high imaging performance and reduces light falloff.

High-resolution performance

As a lens exclusively designed for digital SLR cameras, this zoom lens delivers high resolution and contrast performance for outstanding image quality with sufficient flatness of the field under an extremely wide range of photographic conditions.

Thorough countermeasures, including advanced internal surface coatings, prevent ghosting and flare

Tamron employs multi-layer coatings in order to reduce reflections on lens surfaces as well as internal surface coatings (coatings on the cemented surfaces of lens elements) in order to minimise reflections from the sensor itself within the mirror box, a problem inherent to all DSLRs.

Zoom power of 15x plus built-in VC mechanism in a remarkably slim maximum diameter under 80mm

A lens with the world’s first and greatest zoom ratio of 15x inevitably entails a larger travel distance of the components within its optical systems. But these optics, plus the VC mechanism, are contained in a remarkably slim, compact casing. Engineering this unique zoom lens required complex optical/mechanical components and innovative manufacturing techniques including methods of further enhancing accuracy, reducing weight, and increasing the strength of many components.

Note: Metal mounts are used in both Canon-mount and Nikon-mount lenses.

Zoom lock mechanism for convenience in carrying the outfit

The lens has a built-in zoom lock mechanism to prevent its barrel from sliding forward or down when the lens is being carried on the camera.

Flower-shaped lens hood as a standard accessory

The lens is supplied with a flower-shaped lens hood as a standard accessory. It is designed to efficiently cut harmful light entering at angles other than intended angles at all four corners of the frame. This ensures clear, flare-free images.

New outer design matches the newest generation high power zoom lens in the digital era

1. The lens employs a new outer design that is more refined and smoother in its overall contours by minimising concavity, convexity, and variations in profile in order to match the latest digital SLR cameras.
2. A gold-coloured metal ring is placed at a key portion of the lens as used in other Di II lenses. The TAMRON logo, placed in the centre portion of the lens, enhances visibility of the brand while refining the overall design.
3. Delicate matte finish is added to the black paint over the lens barrel in order to enhance the high quality appearance of the lens.
4. The textured rubber pattern of the zoom and focus control rings has been improved again to a more pronounced, easy to grasp design, compared to conventional rubber patterns. It provides better feel and touch in manipulating the lens.
    

SPECIFICATIONS

* Dimensions are those of a Nikon-mount version of this lens.
** Cosmetic design, specifications and performance are subject to change without notice.

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.

 Vibration Compensation

Tamron's unique VC mechanism uses a proprietary actuator and algorithms to deliver an extremely stable viewfinder image with excellent tracking. The mechanism employs three driving coils which activate the shake-compensating VC lens group electromagnetically via three steel balls. The VC lens elements are held in place only by contact with the steel balls, achieving smooth movement with minimal friction. The simplicity of this mechanical structure is also one of the secrets of Tamron's compact lens sizes.

 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.