Nikon’s exclusive Silent Wave Motor (SWM) enables ultra-fast, ultra-quiet autofocusing with seamless manual focus override. Source: Internet
This extraordinary focusing motor uses ultrasonic vibrations—rather than a gear system—to spin the lens barrel, resulting in nearly silent and ultra-fast autofocusing. Source: Internet
This autofocusing system facilitates Sony's claim that the camera has the fastest AF in the world, for those cameras with APS-C sized sensors at least anyway – and that claim stretches to DSLRs as well as other compact system cameras. Source: Internet