Image Stabilisation

Camera shake is the thief of sharpness. The tremble of your hand as you hold the camera, the slight jarring when you press the shutter release – even a tiny movement during the exposure can result in blurring in the image.

Much of the time, you won't notice the effects of camera shake. If you're shooting with a fast shutter speed or a wide-angle lens, the blurring may not be significant enough for you to register it – but it will still be there, and it might become noticeable if you make a dramatic crop or a large print of the image.

The obvious way to eliminate movement of the camera during the exposure is to fix it to something that will not move, such as a tripod, and to take precautions against jarring it, such as using a remote shutter release. However, a tripod is effective only if it is sturdy, which usually means heavy, so you can't always carry one with you. There are also many situations where a tripod is just not practical, and several where the use of a tripod is not permitted.

Fortunately, Canon offers another method of reducing, if not eliminating, the effects of camera shake: Image Stabilisation (IS).

There are various kinds of IS. Let's start with lens-based ("optical") IS.The first lens with Image Stabilisation was introduced in 1995. It approached the problem of camera shake laterally. Rather than trying to stop the camera moving, a stabilised lens introduces a compensating movement within it, with the aim of keeping the image static on the camera's sensor.

Image Stabilisation was available for camcorders long before it was introduced in EF lenses. Even when both electronic and optical systems were available, size or weight constraints meant that neither was suitable for EOS cameras. So Canon went back to the drawing board and took a fresh look at the problem.

Canon's solution was to use a group of elements inside the lens that move perpendicularly to the lens axis to counteract camera shake. The movement of this special lens group is controlled by an on-board processor, and crucially, there is no reduction in the optical performance of the lens.

With a stabilised lens, camera shake is detected by two gyro sensors inside the barrel, one for yaw (side-to-side movement) and one for pitch (up-and-down movement). The sensors detect both the angle and speed of the movement.

The following sequence of events takes place when the camera shutter release button is partially depressed:

• The special stabilisation lens element group, which is locked in a central position when not active, is released.
• Two gyro sensors start up and detect the speed and angle of any camera/lens movement.
• The gyro data is passed to a microprocessor in the lens, which analyses it and formulates an instruction for the special stabilisation lens element group.
• This instruction is transmitted to the stabilisation lens element group, which then moves at the appropriate speed and direction to counteract the camera movement.
• This complete sequence is repeated continuously, so that there is an instant reaction to any change in the amount or direction of the camera shake.

Optical Image Stabilisation is effective with movement across a range of frequencies, so it can cope not only with simple camera shake (0.5Hz to 3Hz), but also with the engine vibrations encountered when shooting from a moving vehicle or helicopter (10Hz to 20Hz).

When the first EF lens with IS was introduced, it was the first time that a high speed 16-bit microprocessor had been incorporated in a lens. The processor simultaneously controlled the Image Stabilizer, Ultra Sonic Motor (for focusing the lens) and the electromagnetic diaphragm (for setting the lens aperture).

The power required by the image stabilisation system in a lens comes from the camera battery. This means that the battery life is slightly reduced when an IS lens is mounted on the camera and IS is switched on.

One problem with the first EF lenses with IS was that the system saw a panning movement as camera shake and tried to overcome it. This caused the viewfinder image to jump about, making it difficult to see and frame the subject accurately.

On more recent IS lenses, you have the option of two or three IS modes, as follows:

Mode 1 (standard): When IS Mode 1 is selected on a stabilised lens, the IS system works in the same way as the original system and will correct both pitch and yaw movements. It is the best mode to use when you're photographing static subjects.

Mode 2 (panning): Mode 2 is the best setting to use when you're panning the camera to follow a moving subject. It sets the lens to ignore the panning movement and compensate only for movement that is perpendicular to the panning direction. It also ensures a smoother image in the viewfinder.

The IS system automatically detects the direction of the pan, so there's no need to worry about whether you are composing portrait-format or landscape-format images or which direction you are moving the camera.

Mode 3 (during exposure only): Image Stabilizer Mode 3 was introduced in 2010 with the EF 300mm f/2.8L IS II USM and EF 400mm f/2.8L IS II USM (now succeeded by the EF 400mm f/2.8L IS III USM) lenses. It's also built into a number of telephoto and zoom lenses in Canon's EF lens and RF lens lineups, including the RF 70-200mm F2.8L IS USM and RF 100-500mm F4.5-7.1L IS USM.

This useful mode takes the benefits of standard IS (effective for both horizontal and vertical camera motion) but, instead of it being active all the time, it activates only when you fully press the shutter button to capture an image.

Mode 3 is especially useful for sports photography where you are likely to be moving between subjects quickly. In IS Mode 1 this can create a bump or jump within the viewfinder as the IS races to keep up with the lens movements. Instead, by not activating until the shutter button is fully pressed, it saves the system trying to compensate for random, rapid lens motion and compensates only at the point you are taking an image.

Also, by limiting the activation to the point of capture, it ensures that the stabilisation group is centred within the barrel, therefore offering the maximum degree of stabilisation.

Some EF, EF-S, RF and RF-S lenses with IS have automatic panning detection instead of a mode switch. On the RF 24-105mm F4-7.1 IS STM or RF 100-400mm F5.6-8 IS USM, for example, with IS activated, the technology is designed to detect intentional panning movement and switch automatically from Standard IS mode to Panning IS mode.

The EOS R7 and EOS R10 both have the option of a new Scene Mode named Panning Mode. Whereas IS Mode 2 deactivates horizontal stabilisation when you're panning horizontally (as you usually would), the Panning Scene Mode can detect the subject you're following and activate horizontal correction when needed in addition to vertical to help keep the subject framed as desired.

Introduced with the EF 100mm f/2.8L Macro IS USM lens in 2009, Hybrid IS takes the image stabilisation concept and applies it to macro photography. When you're using longer lenses or in general purpose shooting, camera shake appears to be rotational – that is, an up-and-down (pitch) or side-to-side (yaw) movement around a point, that point being the camera. This is effectively corrected by the IS motors contained in the lenses. However, when you move in close for macro photography, the camera shake motion appears to be less rotational and more shift based – as if the whole frame is shifting up-and-down or side-to-side parallel to the subject. This is what Shift IS, found in the Hybrid IS system, aims to correct.

Canon's Hybrid IS technology incorporates an angular velocity sensor, as used in all its IS lenses, which detects the extent of angular camera shake, plus an additional acceleration sensor that determines the amount of shift-based camera shake. The processor combines the output of the two sensors and moves the lens elements to compensate for both types of movement. Hybrid IS dramatically enhances the effects of IS especially during macro shooting, which is difficult for conventional image stabilisation technologies.

The effectiveness of IS may vary, depending on the user's individual ability, but as a general guide the earliest IS lenses enabled sharp images to be captured at shutter speeds about two stops slower than normal. This means, for example, if you can obtain a sharp image shooting handheld without Image Stabilisation at a shutter speed of 1/60 sec, then you will produce results of similar sharpness at 1/15 sec with Image Stabilisation, other factors staying the same.

One of these factors – a key one to consider – is the lens focal length. Increasing the focal length not only magnifies the subject, it also magnifies the effects of camera shake. A useful rule of thumb is that, without IS, you should use a shutter speed at least equal to the reciprocal of the focal length when holding the camera and lens by hand. So if you're shooting handheld without IS and the focal length of the lens is 500mm, then the shutter speed should be at least 1/500 sec. If the lens you're using offers 2 stops of IS, then you can expect to be able to use a shutter speed of 1/125 sec instead (that is, 2 stops slower than 1/500 sec) and still get a sharp shot. More recent IS lenses have improved their effectiveness, giving a 4-stop or a 5-stop gain. A 4-stop gain means that instead of 1/500 sec you should be able to go to 1/30 sec, while 5-stops will take you to 1/15 sec. Or to put it the other way around, a 5-stop gain means that shooting with a shutter speed of 1/15 sec with Image Stabilisation gives the same image sharpness as shooting at 1/500 sec without Image Stabilisation.

Keep in mind that Image Stabilisation only reduces the effect of camera shake − it has no effect on blurring caused by subject movement.

The optical Image Stabilisation system we've been talking about – gyros, microprocessor and special lens element group – is part of the lens, not the camera. This means that the IS can be optimised for each specific lens, and that the IS will work regardless of which camera you use the lens with. In some circumstances you might see the image move in the viewfinder after exposure, but this will not affect the sharpness of the exposed image.

In 2018, building on the Combination IS system used in Canon's EOS M mirrorless cameras, the Canon EOS R introduced a Dual Sensing IS system, which uses information from both the camera and the lens to improve the effectiveness of the optical IS. The system acquires both camera-shake data from a gyro sensor in the lens and motion vector data from the camera's CMOS imaging sensor, enabling it to accurately detect and compensate for low-frequency (slow) blur that used to be hard to detect with gyroscopic sensors alone.

Note that Image Stabilisation does not operate with most EOS cameras if you're using Bulb mode for long exposures. IS is likely to be ineffective for long exposures in any case, and you'll get better results switching off IS and ensuring the camera is secured against any movement.

So far we have only been speaking about the optical IS found in lenses, but the EOS R5 and EOS R6, released in 2020, introduced 5-axis In-Body Image Stabilisation (IBIS) for the first time in Canon cameras, subsequently included in some other models in the range as well. IBIS moves the imaging sensor in order to compensate for camera movement and maintain a steady image.

IBIS operates in tandem with the IS in lenses and is particularly effective against low-frequency vibration (such as that caused by your breathing and heartbeat) and at wider focal lengths, while optical in-lens IS is especially effective at telephoto focal lengths. The in-body and in-lens IS systems working together can deliver a groundbreaking 8-stops of combined IS, depending on the lens.¹ With some lenses with a large image circle, such as the RF 28-70mm F2L USM and RF 85mm F1.2L USM, the camera's IBIS can deliver up to 8-stops of IS even though the lenses do not have built-in optical stabilisation.

The EOS R7 delivers up to 7-stops of IS when paired with RF-S lenses such as its RF-S 18-150mm F3.5-6.3 IS STM kit lens,² which has a smaller image circle designed to match the camera's APS-C sensor. However, the EOS R7 has the same IBIS system as its stablemates and will deliver the same 8-stops of IBIS when using certain full-frame lenses such as the RF 28-70mm F2L USM or the RF 24-70mm F2.8L IS USM, for example. This is because the large image circle of these lenses gives the sensor more room to move and compensate for a greater degree of shake.

In practical terms, following the examples we used above, 8-stops of IS means you may be able to shoot handheld with a 500mm lens at 1/2 sec, and in fact with a wide-angle lens you could possibly shoot handheld with a 4-second exposure. That's long enough to blur moving water but still keep the landscape sharp without the need for a tripod.

When you're using a lens with an IS switch on a camera with IBIS, this switch controls both optical IS and IBIS – they're either both on or both off. If you're using a lens without IS or a lens without an IS switch (such as the RF-S lenses), then you can use camera settings to have IBIS always on (analogous to Mode 1 above) or active only when you take a shot (analogous to Mode 3).

In the EOS R7, the IBIS also enables a new Auto-Level feature, which uses the sensor's rotation capability (roll correction) to get the horizon level in your shots. The sensor rotates through only a very limited range, however, so this won't work with severely tilted horizons, but the feature operates whether the camera is in landscape or portrait orientation, and the result is shown in the viewfinder and rear screen display.

Find out more about In-Body Image Stabilisation in EOS R System cameras.

All the IS systems we've mentioned operate whether you're shooting stills or video, in different combinations according to the lens in use and the IS technologies available. The table below summarises this collaborative approach to image stabilisation in cameras with IBIS. Also, additional technologies for steadying video footage have continued to evolve. Many of Canon's Cinema EOS pro video cameras, for example, use an advanced 5-axis Electronic IS (EIS) system. EOS R System still and video cameras have Movie Digital IS, which in models with IBIS uses all three technologies – lens, IBIS and digital – to enhance stability.

Recent firmware updates have improved the Movie Digital IS performance in the EOS R3, EOS R5 and EOS R6, remedying the slight wobble in the corners of the frame that could sometimes appear in footage shot with ultra-wide lenses.

IS lenses work well when used with accessories. For example, they are very useful when you add a lens extender to increase the effective focal length of the lens by 1.4x or 2x. As already mentioned, increasing the focal length means that the effects of camera shake are magnified, so the IS is extremely beneficial.

Canon EF extenders are compatible with L-series and DO lenses of focal length 135mm and greater, and a small number of wide-aperture telephoto zoom lenses. Canon RF extenders are compatible with RF lenses above 300mm. Both are also compatible with many IS lenses.

Image Stabilisation also remains effective when extension tubes or close-up lenses are used.

Although an IS lens gives more opportunities for handheld shots, there will still be times when the support of a tripod is needed − with exposure times of several seconds, for example, or when you're working with heavy lenses.

With some of the earlier lenses, you needed to switch the IS off when using a tripod as the lack of movement confused the system and the image started to jump around the viewfinder. However, even when using a tripod, there can be some camera movement in high wind or with super telephoto lenses, which means the IS system can be invaluable. More recent IS lenses are able to detect the use of a tripod and automatically disable the IS, if necessary.

You should also leave the Image Stabilisation on when using a monopod, as it is unlikely you will be able to keep this type of support perfectly still.

¹ 8-stops of IS based on the CIPA standard with the RF 24-105mm F4L IS USM lens at a focal length of 105mm.

² 7-stops of IS based on the CIPA standard with RF-S 18-150mm F3.5-6.3 IS STM at a focal length of 150mm.

3 As of May 2022. Except RF 600mm F11 IS STM and RF 800mm F11 IS STM.