April 5, 2012, Saitama, Japan － Tamron Co., Ltd. (President & CEO: Morio Ono / Headquarters: Saitama City), a leading manufacturer of optical equipment, announced the introduction of the SP 24-70mm F/2.8 Di VC USD (Model A007), the world's first*1 full-size high-speed standard zoom lens equipped with VC (Vibration Compensation) image stabilization and USD (Ultrasonic Silent Drive)*2, with resolution at the top of its class. The Canon mount will be released in Japan on April 26, 2012, with the sales dates of Nikon and Sony*3 compatible mounts to be announced later.
SP 24-70mm F/2.8 Di VC USD (Model A007)
|Angle of view(diagonal)||84°04' - 34°21' (with full-size SLR cameras)
60°20' - 22°33' (with APS-C sized sensor digital SLR cameras)
|Lens construction||17 elements in 12 groups|
|Minimum focus distance||0.38m (15.0 in)|
|Maximum magnification ratio||1:5 (at f=70mm: MFD 0.38m)|
|Length*1||108.5mm (4.3 in)*|
|Entire length*2||116.9mm (4.6 in)*|
|Diameter||φ88.2mm (3.5 in)|
|Weight||825g* (29.1 oz)|
|No. of diaphragm blades||9 (rounded diaphragm)|
|Standard accessories||Flower-shaped lens hood|
|Compatible mounts||Canon, Nikon, Sony|
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 ceramic balls. The VC lens elements are held in place only by contact with the ceramic 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.
In the ultrasonic motor, a piezoelectric element arranged in a ring formation generates ultrasonic vibrations in a metallic ring stator, and the vibration energy is used to rotate a metallic ring rotor that is attached to the stator. The rotation energy is in turn transferred from the metallic ring rotor to operate the focus lens.
Since the introduction by Tamron of the first Nikon mount lens featuring an internal AF motor, the AF28-300mm F/3.5-6.3 XR Di VC (Model A20), all Nikon mount lenses with the internal AF motor had used the classification code "N II." Lenses using a coupler system* without an internal AF motor were designated as "N." Because future Nikon lenses will have the internal AF motor as a standard feature, Tamron has decided to simplify the designation and consolidate all Nikon mount lenses as "N," eliminating the "N II" designation for future models. This classification code change will be effective beginning with the 18-270mm F/3.5-6.3 Di II VC PZD (Model B008).
The "N" classification lenses with coupler systems are SP AF200-500mm F/5.6-6.3 Di (Model A08) and SP AF180mm F/3.5 Di (Model B01).