The Tamron 24-70mm f2.8 Di VC USD SP Lens is a high-speed, standard zoom, Super Performance (SP) Lens with built-in Vibration Compensation (VC) and Ultrasonic Silent Drive (USD). Tamron’s VC enables you to shoot hand-held in dimly lit conditions and use speeds up to four stops slower than normal. This compact, lightweight lens incorporates special high-grade glass in three LD elements, three glass molded aspherical lenses, one hybrid aspherical lens and two Extra Refractive (XR) elements to deliver exceptional images. The USD provides quick AF (Auto Focus) that’s quiet, together with full-time manual focus override. Along with its moisture-resistant construction, the Tamron 24-70mm f2.8 Di VC USD SP Lens is equipped with a fast maximum aperture of f2.8 to ensure natural out-of-focus areas with a shallow depth of field.
VC (Vibration Compensation)
VC (Vibration Compensation) is Tamron’s proprietary image stabilization system. Tamron’s VC is 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. And as the VC lens may be moved in parallel using only the motorized control, the mechanical structure has been simplified, enabling the creation of a more compact lens.
New VC system (moving coil method)
Tamron’s original VC image stabilization mechanism utilized a moving magnet system whereby a heavy magnet was positioned near the moving VC lens element. In the new VC unit the positions of the magnet and the coil are reversed, because of this the VC optical lens element is attached to the coil. The new VC mechanism employs a moving coil mechanism with a lightweight coil, and the lighter coil reduces the load on the drive system. Thus, the lighter, more compact new VC unit contributes to the lens’s overall light weight and compact size.
Because the 24-70 mm F/2.8 Di VC USD is a high-speed zoom lens with maximum aperture of F/2.8, its VC system must drive a lens that is larger and heavier than other zooms. Therefore, the shape, size and layout of the drive coils are all designed to obtain sufficient thrust. The result is a full-size, high-speed zoom that provides the same high level of compensation effect.
Digitally Integrated Design – A Generation of lenses designed for optimized use with digital SLR cameras (APS-C format and full-frame) by means of superior designs and multi-coating techniques. The same outstanding performance is also achieved with conventional cameras.
USD ( Ultrasonic Silent Drive)
Tamron’s USD works with high-frequency ultrasonic vibrations which are produced by a ring called a ‘stator’. Energy from the vibrations is used to rotate an attached metallic ring known as a ‘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 of the lens, which is linked to the rotor, is thus moved, creating a fast and smooth auto-focus drive.
SP – Super Performance
Tamron’s Super Performance series is a line of high performance lenses featuring high design specifications.