SLR camera lens What does the USM mean?
Canon ring USM in addition to the basic characteristics of the above, its own characteristics:
6, high efficiency, low power consumption;
7, the ring of the motor can be perfectly combined with the mirror body;
8, low speed, especially for the lens of the AF drive;
9, the rotation speed can be in the range of 0.2rpm ~ 80rpm arbitrary control;
10, can achieve the sensitivity of the electronic MF;
11, the working environment temperature is: -30 ℃ ~ +60 ℃.
USM is the acronym for the Ultra Sonic Motor ultrasonic motor. The USM word on the lens parameters indicates that the lens is using an ultrasonic motor.
USM features are as follows:
1, with low speed and high torque output characteristics;
2, the braking torque is large;
3, simple structure;
4, the motor starts and the controllability of the brake is very good;
5, the sound is very small, almost silent.
Ultrasonic motor.
Of course, the body anti-shake chatter. Think about no matter what the lens, as long as the installation can not achieve anti-shake?
Yes, Canon's "IS" indicates that the lens is able to offset the shaking of the image in a certain range. Anti-shake function
Mud Kang is "VR" to express --- meaning vibration reduction function, the English name vibration reduction.
