| Tamron SP 70-300mm f/4-5.6 Di VC USD
Публикувано във сряда, 10 март 2010 в 14:05 часа от BgFotoNET
От Tamron съобщават, че са създали качествен телезум обектив за пълноформатни дигитални огледално-рефлексни фотокамери. Това е Tamron SP 70-300mm f/4-5.6 Di VC USD. Абревиатурата VC в името идва от “Vibration Compensation” - което ще рече, че обективът е оптично стабилизиран, а абревиатурата USD идва от "Ultrasonic Silent Drive", това е моторът на авто фокуса, който позволява и постоянна употреба на ръчен фокус ако е нужно без да трябва да се превключва в режим MF. В търсене на по-високо качество и по-висока резолюция на изображението, този юбилеен (60 годишнина) обектив на Tamron има модерен дизайн включващ LD (Low Dispersion) и XLD (Extra Low Dispersion) елементи от специален материал, предпазващ от хроматични аберации
Tamron SP 70-300mm f/4-5.6 Di VC USD ще е достъпен за Nikon, Canon и Sony/Minolta AF байонети...
Tamron SP 70-300mm f/4-5.6 Di VC USD
Източник: Прессъобщение на Tamron
Tamron Press Release
Tamron announces the development of its 60th Anniversary Model — the Superior Performance SP 70-300mm F/4-5.6 Di VC USD full-size premium tele zoom
An Extra Low Dispersion (XLD)1 lens made from high-grade materials delivers best in class resolution. Tamron’s own Ultrasonic Silent Drive (USD)2 and Vibration Compensation (VC) make the lens fast, quiet and easy to use.
March 9, 2010, Commack, NY— President and CEO Morio Ono of optical equipment manufacturer Tamron Co., Ltd., announced another advance in Tamron’s pursuit of high resolution images in the telephoto lens category with the development of a 70-300mm F/4-5.6 telephoto zoom lens featuring image stabilization––VC (Vibration Compensation) and an ultrasonic auto-focus drive –– USD (Ultrasonic Silent Drive). The SP AF70-300mm F4-5.6 Di VC USD (Model A005) high-resolution DSLR telephoto zoom lens has been produced first for the Nikon mount, with the development of compatible mounts for Canon and Sony3 to follow.
This new telephoto zoom lens is designed for digital SLR cameras and can be used with both full-frame sensor as well as AF 35mm film cameras with a zoom range of 70-300mm; and with APS-C sensor cameras where the angle of view will change the zoom range equal to 109-465mm4.
With superior optical performance, Tamron’s own USD (Ultrasonic Silent Drive) and VC (Vibration Compensation), the SP 70-300mm F4-5.6 Di VC USD (Model A005) provides the performance of a high-end premium telephoto zoom that is appealing to a broad spectrum of photography enthusiasts.
Unparalleled optical performance in a fast and steady telephoto zoom lens
In the pursuit to achieve the most outstanding image resolution in the 70-300mm class, Tamron’s 60th Anniversary lens - the SP AF70-300mm F4-5.6 Di VC USD (Model A005) - utilizes an advanced optical design that features an LD (Low Dispersion) and an XLD (Extra Low Dispersion) lens element made from specialized materials that prevent chromatic aberration. As a result, the SP AF70-300mm Di VC USD boasts sharper contrast and greater descriptive performance than all others in its class.
In addition, it is the first Tamron lens sporting a USD (Ultrasonic Silent Drive), Tamron’s very own ultrasonic auto-focus drive mechanism. This USD mechanism delivers fast focusing, making it a perfect telephoto zoom choice for photographing sports, racing, and other fast-moving subjects. The lens also boasts Tamron’s proprietary VC (Vibration Compensation) image stabilization to assist in hand-held shooting, not only at long focal length ranges where blurring is common, but also under low-lit conditions, dramatically enhancing photographic freedom.
This combination of best in class image resolution, Ultrasonic Silent Drive and Vibration Compensation is a new achievement of Tamron technology, culminating in the production of a premium 70-300mm telephoto zoom lens.
New optical system optimized for digital cameras achieves top resolution in the 70-300mm class with specialized glass elements including an XLD (Extra Low Dispersion) lens element
This lens’ advanced optical design employs a sophisticated XLD (Extra Low Dispersion) lens element made from specialized high-grade glass that has lower dispersive properties than standard LD lenses (where refraction causes the dispersion of white light into spectral hues). The dispersive properties of the XLD lens are at a level similar to fluorite, and in combination with LD elements make for an optimal optical design that delivers best in class resolution with advanced axial chromatic and magnification aberration correction - major inhibitors of image quality enhancement. The result is a lens that delivers sharp contrast and better descriptive performance throughout the entire zoom range.
Fast focusing with USD (Ultrasonic Silent Drive), Tamron’s ultrasonic autofocus drive
The lens is equipped with Tamron’s first-ever ultrasonic auto-focus drive USD (Ultrasonic Silent Drive). It achieves faster focusing making this telephoto lens perfect for photography of sports, motor racing, and other fast-moving subjects. With advanced motor technology and newly developed software, Tamron’s USD delivers precise and noiseless focusing at turbo speed.
USD (Ultrasonic Silent Drive)
Tamron’s USD works with the high-frequency ultrasonic vibrations that are produced by a ring called a ‘stator’. Energy from the vibrations is used to rotate an attached metallic ring known as the ‘rotor’. Piezoelectric ceramic, an element that produces ultrasonic vibrations when voltage of a specific frequency is applied is arranged in a ring formation on the stator. This electrode configuration of piezoelectric ceramic causes two ultrasonic vibrations to occur in the stator.
By effectively combining these two ultrasonic vibrations, it is possible to convert the energy from the vibrations that produced simple motion into energy known as ‘deflective traveling waves’, which then moves around the circumference (rotation direction) of the ring.
With the USD, the friction between these deflective traveling waves created on the metallic surface of the stator and the surface of the rotor produce force, causing the rotor to rotate. The focusing ring lens, which is linked to the rotor, is thus moved, creating a fast and smooth auto-focus drive.
Equipped with Tamron’s VC (Vibration Compensation) image stabilization
The SP 70-300mm F4-5.6 Di VC USD employs Tamron’s esteemed image stabilization mechanism–VC (Vibration Compensation) seen in both the AF18-270mm Di II VC (Model B003) and SP AF17-50mm F/2.8 XR Di II VC (Model B005). With VC, the photographer has the freedom to shoot at a shutter speed that is an extra four stops slower without having to worry about blurring. This makes capturing handheld, evening, night, and interior shots much easier.
VC (Vibration Compensation)
Tamron’s VC mechanism employs a three-coil system, whereby three driving coils 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 little friction. This provides a stable viewfinder image with excellent tracking performance that eliminates the blur from camera shake for cleaner, crisper shots.
Full time manual focus at your fingertips
Auto-focus has many benefits but sometimes the photographer needs the control of manual focus. Full time manual offers just that: the crossover from auto-focus to manual focus by simply adjusting the focus ring, allowing the photographer to make adjustments on the fly. This feature helps the lens produce impressive results even in telephoto situations where the depth of field is narrow.
Better balance and consistent length with internal focusing
When focusing, the internal elements of the lens move and the lens’ external size does not change. This offers better balance and easier telephoto shots. Moreover, the barrel is not subject to stray light entering from external helicoids that can negatively affect images. And because the external elements do not move, it makes it easier to utilize polarizing filters and the flower shape hood to control the amount of light that enters the lens.
Enjoyable photography for a wide range of enthusiasts, from those using traditional film cameras, to digital SLRs with full-frame or APS-C size sensors
With a full-frame digital or 35mm SLR, portrait and medium telephoto shots can be achieved on the wider 70mm end of the range and spectacular telephoto shots at the longer 300mm side. When using an ASP-C sensor camera the angle of view changes, giving it the equivalent range of 109-465mm for bold ultra-telephoto shots. And with a maximum magnification ratio 1:4, the lens can be used to explore in the realm of semi-macro photography.
Uncompromising countermeasures to reduce ghosting and flare
Digital photography requires extreme precision, which is why Tamron incorporates new BBAR (Broad-Band Anti Reflection) multilayer coatings that reduce reflection into the lens elements. This ensures excellent performance in all photographic conditions and enhances light transmission on both long and short wavelengths. In addition, Tamron applies internal surface coatings on cemented surfaces of lens elements to make images sharper with better color reproduction and balance.
Simple yet beautiful exterior design
Tamron adopted a simple design with a smooth silhouette to ensure that this lens fits well with various SLR cameras. The exquisite textured paint gives a well-crafted finish to the exterior.
Flower-shaped hood with excellent stray light shielding properties–a standard accessory
The flower-shaped hood has been designed specifically to block out damaging light rays and ensures clear, sharp descriptive performance.