The AF drive of the 50-300mm F4.5-6.3 VC uses TAMRON's VXD (Voice-coil eXtreme-torque Drive) linear motor focus mechanism. This AF system allows comfortable focusing from the MOD (Minimum Object Distance) through infinity with high-speed and high-precision performance that represents the highest level in TAMRON’s history. Tracking performance for moving objects is also outstanding, making it perfect for shooting subjects that move in unpredictable ways such as children engaged in sports and spectator events like baseball, rodeos, and auto racing. These features ensure you can capture once-in-a-lifetime photo opportunities without missing the shot. In addition, because the quietness offered by the linear motor system provides nearly silent operation, reducing the noise from vibration and focus driving, the lens can also be used with confidence when shooting still images or filming in quiet settings.