Canon lenses employ two different kinds of autofocus systems: STM and USM. Both Canon DSLR cameras and mirrorless cameras can use these 2 kinds of lenses. If you’re looking to buy a Canon lens for your camera body, you might be puzzled by the differences between these two lens types. Let’s examine the main distinctions between STM and USM lenses.
The Key Differences Between STM and USM:
Stepper Motor is abbreviated as STM, and Ultrasonic Motor is abbreviated as USM. For autofocusing, a stepper motor is utilized within a Canon STM lens. For autofocusing, the Canon USM lens employs an Ultrasonic motor.
During autofocusing, Canon’s USM lenses make a little amount of noise. The stepper motor in Canon’s STM lenses has helped to alleviate this noise problem. The noise in the USM lens is caused by the rapid movement of internal lens components. So, if you want a lens that doesn’t create a lot of noise while autofocusing, go for an STM lens.
Manual Focus Factor:
There are occasions when you’ll want to employ your lens’ manual focus mode. A “Focus by wire mechanism” is used in the STM lens. A signal is delivered to the motor to move the focus elements when you try to rotate the manual focus ring on an STM lens. As a result, the focal components are shifted in an indirect manner. As a result, there will be a latency while manually focusing. In the case of a USM lens, however, the movement of the focus rings directly moves the lens components within. It enables for continuous manual focus without causing any harm to the motor.
When it comes to lens selection, price is a critical issue. Canon USM lenses are more expensive than Canon STM lenses. So, if you’re on a tight budget, the STM lens is the way to go.
Canon’s USM lenses are quicker than their STM counterparts in terms of focusing. As a result, they are quicker than STM lenses. So, if you’re searching for a lens with quick autofocus, the USM lens is the way to go.
If there are two subjects in the picture that are separated by a significant distance and you want to shift the attention from the front to the back. The phase detection technology in the USM lens will aid in achieving a quick focus lock. You should use USM lenses for wildlife photography because of this feature. For animal and bird photography, the ability to focus quickly is critical.
Using For Photography:
I strongly advise you to get Canon USM lenses if you want to invest in professional grade lenses for photography. The USM lens’s quick focusing function makes it more photographer-friendly. The Canon L series houses the majority of USM lenses, ensuring that they are made of high-quality glass. As a result, the picture quality will be improved. The USM lens is the perfect choice if you’re into action photography, sports photography, wildlife photography, or bird photography.
Using For Videos:
If you’re shooting videos using your camera, you’ll also be capturing audio. When aiming to focus on the topic, the USM lenses will produce noise. The camera’s microphone/an external microphone will take up this noise (if the external mic is very close to the camera). As a result, the video’s audio will be of poor quality. If you’re shooting video with a USM lens, it’s best to use an external microphone that’s kept away from the camera. It will assist in avoiding the pickup of motor noise while autofocusing. The STM lenses assure that no sound is created during video capture, and no lens noise is picked up in the audio. STM lenses create smoother, less jarring videos.
The STM lenses, in comparison, are nearly quiet, as they were designed with video in mind – rodents need not apply. While slightly slower, their focus speed is considered suitable for video since it is smoother and less “jarring.”
Both STM and USM lenses have advantages and disadvantages. The decision between the two will mostly be based on your intended application (video or photography) and financial constraints. If you’re a professional photographer, a USM lens is the way to go. Invest in an STM lens if you intend to record movies. Noise-free footage will be captured thanks to the silent AF and smooth focus.