"STM" stands for stepping motor. This motor is synchronized and operated by pulse electricity which facilitates quick response time during start-up and power-down, and a high level of controllability. Structural simplicity promotes smooth and silent operation while allowing for a compact design.

As of July 2014, the Canon EF-S series includes four lenses equipped with STM. All of them are high-performance, high-magnification zoom lenses, and each of them is equipped with an Image Stabilizer (IS*).

• EF-S18-55mm F3.5-5.6 IS STM
• EF-S18-135mm F3.5-5.6 IS STM
• EF-S55-250mm F4-5.6 IS STM
• EF-S10-18mm F4.5-5.6 IS STM

"IS" stands for Image Stabilizer.

* Only the following cameras are compatible with EF-S lenses:

EOS 7D Mark II, EOS 7D, EOS 70D, EOS 60D, EOS 60Da, EOS 50D, EOS 40D, EOS 30D, EOS 20D, EOS 20Da, EOS REBEL T5i / EOS 700D, EOS REBEL T4i / EOS 650D, EOS REBEL SL1 / EOS 100D, EOS REBEL T3i / EOS 600D, EOS REBEL T2i / EOS 550D, EOS REBEL T1i / EOS 500D, EOS DIGITAL REBEL XSi / EOS 450D, EOS REBEL T5 / EOS 1200D, EOS REBEL T3 / EOS 1100D, EOS DIGITAL REBEL XS / EOS 1000D, EOS DIGITAL REBEL XTi / EOS 400D DIGITAL, EOS DIGITAL REBEL XT / EOS 350D DIGITAL, EOS DIGITAL REBEL / EOS 300D DIGITAL

1. The Image Stabilizer gives the equivalent effect of a shutter speed four stops faster(*1).

This function provides optimal image stabilization depending on shooting conditions (such as shooting still subjects and following shots).

2. Aspherical lens elements result in outstanding image delineation.

3. Electronic manual focusing made possible by electronically detecting the rotation of the focusing ring.

4. Manual focusing is available after the subject comes into focus in autofocus mode (ONE SHOT AF).

5. Circular aperture for producing beautiful softfocus images.

6. Improved Movie Shooting Functions

• Stepping motor achieves quiet, smooth Movie Servo AF(*2).

*1: Based on [1/(focal length x 1.6)] second. Generally, it requires a shutter speed [1/focal length] second or faster to prevent camera shake (in 35mm format. With an EF-S lens, it would be [1/(focal length x1.6)] second).

*2: Applies to EOS 7D Mark II, EOS 70D, EOS REBEL T5i / EOS 700D, EOS REBEL T4i / EOS 650D, EOS REBEL SL1 / EOS 100D, EOS M2 (*3) (when the EF-EOS M mount adapter is attached), and EOS M (when the EF-EOS M mount adapter is attached).

*3: Not available in certain countries and regions.

1. The Image Stabilizer gives the equivalent effect of a shutter speed four stops faster(*1).

This function provides optimal image stabilization depending on shooting conditions (such as shooting still subjects and following shots).

2. Aspherical and UD lens elements result in outstanding image delineation.

3. Electronic manual focusing made possible by electronically detecting the rotation of the focusing ring.

4. Manual focusing is available after the subject comes into focus in autofocus mode (ONE SHOT AF).

5. Circular aperture for producing beautiful softfocus images.

6. Improved Movie Shooting Functions

• The EF-S18-135mm f/3.5-5.6 IS STM is equipped with dynamic IS, effective when shooting while walking since it expands the IS range.
• Stepping motor achieves quiet, smooth Movie Servo AF(*2).

*1: Based on [1/(focal length x 1.6)] second. Generally, it requires a shutter speed [1/focal length] second or faster to prevent camera shake (in 35mm format. With an EF-S lens, it would be [1/(focal length x1.6)] second).

*2: Applies to EOS 7D Mark II, EOS 70D, EOS REBEL T5i / EOS 700D, EOS REBEL T4i / EOS 650D, EOS REBEL SL1 / EOS 100D, EOS M2 (*3) (when the EF-EOS M mount adapter is attached), and EOS M (when the EF-EOS M mount adapter is attached).

*3: Not available in certain countries and regions.

1. Improved Movie Shooting Functions

• Stepping motor with lead screws achieves quiet, smooth Movie Servo AF. *1

2. High-speed, quiet Autofocusing achieved during viewfinder shooting.

3. UD lens elements for excellent imaging performance.

4. Equipped with an Image Stabilizer that provides an image stabilization effect equivalent to a shutter speed 3.5 stops*2 faster (telephoto end, when used with the EOS 7D).

The Image Stabilizer also provides optimal image stabilization that responds to shooting conditions (such as shooting still subjects and following shots).

5. Electronic manual focusing (MF) made possible by electronically detecting the rotation of the focusing ring.

6. Manual focusing is available after the subject comes into focus in autofocus mode (ONE SHOT AF).

7. Circular aperture for producing beautiful softfocus images.

*1: Based on [1/(focal length x 1.6)] second. Generally, it requires a shutter speed [1/focal length] second or faster to prevent camera shake (in 35mm format. With an EF-S lens, it would be [1/(focal length x1.6)] second).

*2: Applies to EOS 7D Mark II, EOS 70D, EOS REBEL T5i / EOS 700D, EOS REBEL T4i / EOS 650D, EOS REBEL SL1 / EOS 100D, EOS M2 (*3) (when the EF-EOS M mount adapter is attached), and EOS M (when the EF-EOS M mount adapter is attached).

*3: Not available in certain countries and regions.

1. Improved Movie Shooting Functions

• Stepping motor with lead screws achieves quiet, smooth Movie Servo AF. *1

2. High-speed, quiet Autofocusing achieved during viewfinder shooting.

3. Aspherical and UD lens elements result in outstanding image delineation.

4. Equipped with an Image Stabilizer that provides an image stabilization effect equivalent to a shutter speed 4 stops*2 faster (when the focal length is set to 18 mm, equivalent to 29 mm in the 35mm film format, and when used with the EOS 7D).

The Image Stabilizer also provides optimal image stabilization that responds to shooting conditions (such as shooting still subjects and following shots).

5. Electronic manual focusing (MF) made possible by electronically detecting the rotation of the focusing ring.

6. Manual focusing is available after the subject comes into focus in autofocus mode (ONE SHOT AF).

*1: Applies to EOS 7D Mark II, EOS 70D, EOS REBEL T5i / EOS 700D, EOS REBEL T4i / EOS 650D, EOS REBEL SL1 / EOS 100D, EOS M2 (*3) (when the EF-EOS M mount adapter is attached), and EOS M (when the EF-EOS M mount adapter is attached).

*2: Image stabilization performance based on CIPA (Camera & Imaging Products Association) Standards. During actual shooting, image stabilization performance varies depending on the amount of camera shake, shooting conditions, and other factors.

*3: Not available in certain countries and regions.

1. The motor does not operate while the camera is OFF or when the camera is OFF due to the use of the auto power off function. Therefore, users must be aware of the following points.

• Manual focus adjustments are not possible.
• During zooming, delayed focus will occur.

2. If not operated for a certain period of time, this lens will enter sleep mode in order to save power. Sleep mode differs from when the camera is OFF due to the use of the auto power off function. To exit sleep mode, press the shutter button halfway.

In this state, the motor will not operate even if the camera is ON. Therefore, users must be aware of the following points.

• Manual focus adjustments are not possible.
• During zooming, delayed focus will occur.

3. When the camera is ON or when the camera is turned ON by pressing the shutter button halfway down when the camera is OFF due to the use of the auto power off function(*3), the lens performs an initial reset of the focus lens.

• Although the image in the viewfinder will appear out of focus during the initial reset, this does not mean that the lens has malfunctioned.
• Although the shutter can be released during the initial reset, users must wait approximately 1 second(*4) after the initial reset has completed before shooting.

*3: Applicable to the following EF-S lens compatible digital SLR cameras:

EOS 7D Mark II, EOS 7D, EOS 70D, EOS 60D, EOS 60Da, EOS 50D, EOS 40D, EOS 30D, EOS 20D, EOS 20Da, EOS REBEL T5i / EOS 700D, EOS REBEL T4i / EOS 650D, EOS REBEL SL1 / EOS 100D, EOS REBEL T3i / EOS 600D, EOS REBEL T2i / EOS 550D, EOS REBEL T1i / EOS 500D, EOS DIGITAL REBEL XSi / EOS 450D, EOS REBEL T5 /EOS 1200D, EOS REBEL T3 / EOS 1100D, EOS REBEL XS / EOS 1000D, EOS DIGITAL REBEL XTi / EOS 400D DIGITAL, EOS DIGITAL REBEL XT / EOS 350D DIGITAL, EOS DIGITAL REBEL / EOS 300D DIGITAL

*4: The initial reset time varies depending on camera being used.