South & Southeast Asia
South & Southeast Asia
The Nano Ultrasonic Motor (USM) is a compact ultrasonic motor that supports high-speed AF. It was first introduced in 2016, with the EF-S18-135mm f/3.5-5.6 IS USM lens. Using vibrational energy from ultrasonic waves, the motor moves in a straight line along a slider. The position of the focus lens, which is mounted on a rack-like component, can be adjusted along the optical axis with great precision, thus enabling high-speed AF. The very precise micro-movements of this revolutionary AF actuator helps the lens achieve high performance autofocus for both still photography and movie recording. In 2018, a new type of Nano USM was developed for the first time in an L-series lens. The new Nano USM has been miniaturized to fit within a compact lens barrel, to reduce the overall size of the lens as much as possible. It was first introduced on the RF24-105mm f/4L IS USM lens.
The new design of the Nano USM eliminates the spring that formerly applied pressure to a piezoelectric ceramic element on the back end. This structure has been replaced by springs positioned at the four corners of the unit, to significantly reduce thickness while maintaining high torque. The Nano USM is capable of driving a lens at high speed and stopping it with precision, for high-speed AF when taking still photos. When shooting movies, it achieves smooth and near-silent focus for a wide range of expressive purposes.