Commack, NY—Tamron launched the 70-210mm f/4 Di VC USD (model A034) compact telephoto zoom lens for full-frame DSLR cameras. The new lens is engineered to provide “superb optical performance throughout the entire zoom range and features a maximum magnification ratio of 1:3.1, the highest in its class,” the company announced.
The design includes an internal zoom mechanism. As a result, the physical length of the lens does not change during zooming. This minimizes changes in the center of gravity to provide more stable use and operation. In addition, it’s not necessary for the photographer to move backward when shooting space is limited, for instance, when photographing through a wire mesh fence. Also, so-called “zoom creep” is said to be impossible because the overall length never extends. Furthermore, the nonrotating front element is designed to make the use of polarizing filters easier.
The lens also employs a dual MPU (micro-processing unit) engineered to enable high-speed, high-accuracy autofocus performance as well as VC (vibration compensation) image stabilization. The system uses two MPUs dedicated to VC processing and lens system control. Both MPUs have a digital signal-processing block to improve the computing power of the entire system. VC achieves 4 stops of compensation.
In addition, the optical construction (20 elements/14 groups) uses three LD (low dispersion) lens elements to compensate for axial and transverse chromatic aberrations, to help ensure crisp image quality across the entire frame. Model A034 also features a constant maximum aperture of f/4 throughout its zoom range. As a result, it provides control over depth of field and excellent bokeh. Furthermore, Tamron claims that compared to large-aperture telephoto zoom lenses, the new A034 is lighter and more compact. It weighs 30.3 ounces and measures a total length of 6.8 inches. 
The portable lens also employs an autofocus (AF) drive system that uses a USD (ultrasonic silent drive) ring-type ultrasonic motor for responsiveness. It also helps ensure fast, precise focusing. In addition, it is equipped with a full-time manual focus override mechanism. This permits photographers shooting with AF to instantly make fine manual focusing adjustments without switching the AF-MF mode switch.
For outdoor use, the surface of the front lens element is coated with a protective fluorine compound with water- and oil-repellent qualities. Therefore, the front surface is easier to wipe clean and less vulnerable to the effects of dirt, moisture or oily fingerprints. Furthermore, a moisture-resistant build has seals located at the lens mount area and other critical locations to prevent infiltration of moisture and/or raindrops.
Another feature is a minimum object distance of 37.4 inches. The shorter working distance enables photographers to capture close-up images of small objects while using a telephoto zoom.
70-210mm f/4 Di VC USD Compatibility with Teleconverters
The new lens is also compatible with Tamron’s teleconverter 1.4x (model TC-X14) and teleconverter 2.0x (Model TC-X20). They increase the focal length of the lens to 1.4 times and 2 times the original, respectively.
The A034 also works with the optional Tamron TAP-in Console. This optional accessory provides a USB connection to a computer, so that users can update the lens’s firmware. They can also customize features, including fine adjustments to the AF and VC.
In addition, for rapid attachment to a tripod, an Arca-Swiss style tripod mount is available as an optional accessory. With a hinge-type ring section, connection is said to be easy even when the lens is mounted on a camera. The tripod mount is made of lightweight magnesium alloy.
The lens will be available in Canon and Nikon mounts in April for a suggested retail price of $799. Moreover, an electromagnetic diaphragm system, a standard feature for Canon-mount lenses, is now employed in the Nikon version. The system allows for more precise diaphragm and aperture control because the diaphragm blades are driven and controlled by a built-in motor through electronic pulse signals. tamron-usa.com
