Difference Between USM and IS

The terms "Ultrasonic Motor" (USM) and "Image Stabilisation" (IS) refer to two separate technologies present in current camera lenses.

While USM and IS may appear unrelated, both perform vital functions in helping photographers capture sharp, clean photographs. USM enables photographers to focus on their subject quickly and accurately, while IS decreases the danger of blurry shots produced by camera shake.

Read this article to find out more about USM and IS and how they are different from each other.

What is USM?

A type of focusing motor used in camera lenses is the ultrasonic motor (USM). It drives the lens's focusing mechanism with ultrasonic vibrations, resulting in fast and silent focusing.

The use of ultrasonic vibrations in USM technology allows the lens elements to move quickly and precisely, resulting in fast and accurate focusing. Because of its ability to quickly snap onto a subject, USM is ideal for shooting fast-moving subjects like sports, wildlife, and action photography.

USM is classified into two types: ring-type and micro-type. The ring-type USM uses a ring-shaped motor that encircles the lens barrel and directly drives the focusing mechanism, resulting in rapid and quiet focusing. For especially precise focusing, micro- type USMs use a smaller, lighter motor that moves the focusing elements in small increments.

The USM technology has various advantages over other types of autofocus technologies. It works quickly and softly, making it excellent for photographing subjects without disturbing them. It also supports manual focus override, which gives photographers more control over the focus of their photographs. In addition, USM has a long lifespan and is extremely durable and reliable.

What is IS?

Image stabilisation (IS) is a technology that prevents fuzzy images caused by camera movement by reducing camera movement. IS is a type of stabilisation technology that is often found in camera lenses. It works by using sensors to detect camera movement and then compensating for it by moving the lens elements or the camera's sensor.

IS technology allows photographers to shoot at slower shutter speeds while avoiding blur produced by camera shake, which is especially useful in low-light circumstances or when using longer lens lengths. It is especially useful for handheld photographers because it helps stabilise the camera and remove blur produced by natural hand movements.

IS classified into two types: in-lens and in-body.

  • In-lens IS is built directly into the lens and is unique to that lens.

  • In-body IS is built into the camera itself and works with any lens that is mounted to it.

IS technology having a number of advantages over traditional photographic approaches. It produces sharper photographs, especially in low-light conditions or while shooting handheld. It allows photographers to use slower shutter speeds, resulting in more creative and dynamic photographs.

Difference between USM and IS

The following table highlights the major differences between USM and IS −





Ultrasonic Motor

Sensor-based or Lens-based


Quieter operation, quick focus

Reduces blur, enables slow shutter speeds, and enhances stability.


Ring-type or micro-type

In-lens or in-body


Sports, wildlife, and action shots

Low-light, handheld photography


More Expensive

Less Expensive

Stands for

Ultrasonic Motor

Image Stabilisation


USM is compatible with specific lenses.

IS is compatible with all lenses that are attached to the camera.


In conclusion, USM and IS are two different technologies present in camera lenses that perform different tasks. USM is a type of autofocus motor that enables fast and silent focusing, whereas IS is a technology that reduces camera shake and prevents fuzzy shots.

Both technologies play essential roles in helping photographers capture sharp and clear photographs, and whether to use USM or IS depends on the style of photography being done and the photographer's unique needs.

Updated on: 03-Apr-2023


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