Why is Image Stabilization important?

Many new digital cameras are coming with a feature called image stabilization. Just what is this feature, and is it something you need?

How Image Stabilization Works

Image stabilization is the generic name given to any technology that compensates for what the experts call "camera shake." Camera shake is just what it sounds like -- the effect on your pictures of a shaky camera.

As you've no doubt experienced, it isn't always possible to hold your camera perfectly still when shooting, particularly when you're shooting in low-light situations. When the light is low, the camera uses a slower shutter speed. This results in a longer exposure, which means that the camera lens is kept open longer. The longer the lens is open, the more likely that there will be some noticeable camera movement.

When you accidentally move the camera during a shot, the result is a blurry picture. You can manually deal with this problem by better steadying the camera when shooting, typically by using a tripod. But a tripod isn't always available, which is where image stabilization technology comes in.

Image stabilization doesn’t steady the camera so much as it steadies the elements inside the camera's lens. By steadying the image projected into the camera, blurry pictures are minimized.

One approach to image stabilization utilizes a floating optical element in the lens itself. A camera with image stabilization uses a built-in gyro sensor to detect hand movement and then relay that information to a tiny microcomputer inside the camera. The microcomputer instantly calculates the amount of compensation needed, and a linear motor then shifts the optical image stabilizer lens as necessary, on the fly. The result is less user-induced jitter and shake. This approach is used in some Canon, Nikon, Olympus, Panasonic, and Sony cameras.

Another approach is to move the camera's electronic CCD image sensor (instead of the lens) so that it compensates for inadvertent camera movement. The sensor is mounted on a platform that moves in the opposite direction as the movement of the camera, as determined by a series of motion detectors. This type of system is typically called "anti-shake" as opposed to image stabilization; Konica Minolta uses it in several of their digital cameras.

Why You Need Image Stabilization

Image stabilization isn't new. Manufacturers of high-end zoom and telephoto lenses have been using this technology for some time now, and it's also a popular feature in professional binoculars and some digital video cameras.

The reason image stabilization is so popular is that it makes it easier to take sharp pictures under all lighting conditions. If your camera features image stabilization technology, you stand a much better chance of shooting sharp pictures at the slower shutter speeds used in low-light conditions. In addition, you'll probably notice better sharpness in all your photos, no matter how much light you have.

In technical terms, image stabilization typically enables you to take handheld shots two to three stops slower than with a non-stabilized camera. For example, if you would normally need a shutter speed of 1/500th of a second to shoot a particular scene, adding image stabilization would let you shoot the same scene at only 1/125th of a second.

The bottom line? If your camera has image stabilization, you'll shoot sharper pictures under all lighting conditions. In particular, you'll have fewer blurry pictures when shooting in low light. What's not to like?

Michael Miller is a writer and commentator on technology and digital lifestyle topics.