Image Stabilizer, English name: image stabilizer.

One of the major obstacles in shooting is "jitter". Usually, in order to avoid jitter, it is necessary to adopt a shutter speed faster than "1/ focal length" seconds. However, if you shoot in a dark place or use a low-sensitivity hand-held, you must slow down the shutter speed, which will easily blur the shot picture. The image stabilizer developed by Canon alone compensates for jitter by moving some optical systems in parallel, thus reducing the shooting failure caused by jitter.

In real life, carrying a tripod is a very troublesome thing. For example, when hiking, traveling or using a tripod is not allowed, no matter how stable the hand-held camera is, it is difficult to avoid image blur when shooting in low illumination.

Canon has a solution to this problem. A single-mirror reflective lens with built-in image stabilizer has been successfully developed. According to the vibration angle and times of the lens, the rotating unit of the optical compensation system and the moving optical system will make compensation movement to correct the vibration.

Ultrasonic motor (USM)

The ultrasonic motor (USM) in Canon EF lens is driven by ultrasonic vibration force, which is fast and quiet, making the autofocus operation of EF lens fast, accurate and nearly silent. This direct drive structure is very simple, which improves durability and work efficiency. 

Ultrasonic motors are divided into two types: annular and miniature. The former is mostly used for large aperture and super telephoto lenses; The latter is mostly used for economical lenses. Proper use will make the autofocus effect better.