Tamron's Unique Vibration Compensation Technology

Tamron developed a Vibration Compensation (VC) system that's built into the AF28-300mm F/3.5-6.3 XR Di VC LD Aspherical (IF) Macro and the AF18-270mm F/3.5-6.3 Di-II VC LD Aspherical (IF) Macro lenses.

VC is now commonly used by most leading lens companies. It helps to reduce handheld camera shake by sensing the amplitude and direction of shake and compensating by moving optical groups within the lens. 
Tamron's system can to this much more effectively due to a breakthrough design. 

Tamron's VC system uses a tri-axial configuration, while most other systems can only correct shake on two planes; horizontal and vertical. Tamron's system features three pairs of driving coils and low-friction ball bearings which are placed around the optical group that can compensate for shake. This allows what is basically a free floating shake compensator to be created, which can compensate for camera shake that occurs in a diagonal direction as well as up and down and side to side movements.

The new system is more responsive and durable than previous systems, and both of the mentioned lenses incorporate an accurate and sensitive gyro sensor that can detect even the slightest handshake.

Tamron VC enables you to shoot up to four stops slower at slower shutter speeds.