USM, also known as Ultrasonic Motor, refers to a type of motor commonly utilized in the field of optics, particularly in camera lenses. It is a technology initially introduced by Canon in the early 1990s, which has since become widely adopted by various camera manufacturers.
USM incorporates ultrasonic vibration in order to provide quick and precise autofocus functionality. This motor operates by transforming electrical energy into ultrasonic vibrations, which are then channeled to move the lens elements smoothly and silently. This allows for near-instantaneous and accurate autofocus performance, enabling photographers to capture sharp images with ease.
One of the key advantages of USM is its ability to maintain manual focus override. This feature allows photographers to fine-tune the focus manually even when the camera is set to autofocus mode. When compared to traditional lens motors, USM commonly offers superior speed, smoother operation, reduced noise, and improved autofocus tracking.
Moreover, USM technology has evolved and diversified over time. Different variations have been developed, such as Ring-type USM (USM driven by a ring, allowing for full-time manual focusing), Micro USM (smaller and lower-cost version), and Nano USM (combination of ultrasonic and stepper motor technologies). These variations cater to different camera models, lenses, and specific shooting requirements.
USM has become a benchmark technology in the realm of camera lenses, paving the way for more advanced autofocus systems. Its efficiency, accuracy, and versatility have significantly enhanced the overall photography experience, particularly for professional photographers and enthusiasts who rely on quick and precise autofocus capabilities.
