The difference between stm and usm lenses

The differences between stm and usm lenses are as follows:

1. Focus speed and sound: USM: Ultrasonic motor is a high-speed, high-precision drive system. It focuses very quickly and virtually silently, making it ideal for situations where fast, silent focusing is required. USM lenses are very popular for shooting dynamic scenes or situations where quick focus is required. STM: Stepper motors focus slower than ultrasonic motors, but are still sufficient in many situations. The STM drive system is smoother during the focusing process and is suitable for shooting videos and situations where a smooth focusing process is required.

2. Manual focus adjustment: USM: Most USM lenses have full-time manual focus (Full-TimeManualFocus) function, which means that even in autofocus mode, you can still make fine adjustments through the manual focus ring . STM: Some STM lenses have manual focus, but not all. On some low-end STM lenses, there is no manual focus option.

3. Scope of application: USM: Ultrasonic motors are widely used in Canon’s advanced and professional-grade lenses and are suitable for a wide range of photography fields. STM: Stepper motors are mainly used in some entry-level and mid-level lenses, and are also designed to meet the needs of video shooting and adapt to the needs of entry-level photographers.