The difference between stm and usm lens

There are significant differences between the two lenses in focusing technology, focusing speed, sound, applicability and motor type.

1, focusing technology, STM adopts step-by-step focusing technology, and realizes focusing through tiny step actions. This technology is used in video shooting, which can achieve smooth and continuous focusing. USM uses ultrasonic focusing technology to focus by driving the movement of lens elements. This technology focuses faster and is used for high-end lenses.

2, focusing speed, STM focusing speed is relatively slow, but enough to meet the daily shooting needs. USM has a very fast focusing speed, which is suitable for shooting scenes that need to capture the focus quickly.

3, sound, STM is almost silent when focusing, which is very suitable for scenes that need silent shooting. USM focuses quickly, but it produces slight noise. With the development of technology, some new USM lenses have improved this.

4, applicability, STM is more suitable for entry-level and daily shooting, and the price is relatively more close to the people. USM is used for professional lenses and is suitable for photographers who require high shooting quality.

5. Motor type: STM adopts electronic control focusing ring and stepping motor (divided into lead screw type and gear type), which can get more accurate and smooth focusing effect when manual focusing is used. However, it should be noted that STM motor can only use manual focusing when charging, otherwise it may damage the motor. USM adopts annular ultrasonic motor, which can realize full-time manual focusing. This kind of motor has a large torque and is used to drive a large lens.