Understanding The Role Of Image Stabilization In Digital Photography

Camera shake is a common problem for both beginning and experienced photographers. Even a slight movement can blur an image, ruining the shot. Using a tripod resolves the issue, but can be cumbersome in situations where portability is critical. Years ago, camera manufacturers introduced image stabilization (IS) to address the problem.

This feature helps you take clear shots without using a tripod. While IS does not completely eliminate camera shake, it minimizes its effect to the point most people are unable to recognize it. The result is sharper photographs.

This article will present the basics of image stabilization, beginning with situations that pose a need for the feature, and the different types offered by manufacturers. We'll also provide a few tips for shooting clear images without the aid of IS or a tripod.

To understand the circumstances that call for IS, it is useful to understand how camera shake occurs in the first place. Even the most experienced photographers have difficulty remaining still when they take their shots. Their movements, regardless of how slight, introduce blur into their photos.

In some cases, the effect is minimal. For example, your shooting environment may provide plenty of light, allowing you to use a fast shutter speed. In such cases, a small amount of movement is unlikely to cause substantial blur. Likewise, if you are shooting a close-up, camera shake will have a less-pronounced effect on your images. Making sure that your lighting and distance is correct will help if you decide to alter the image later or blow it up for custom poster printing.

But suppose you are shooting in a low-light environment. In this case, you might need to use a slower shutter speed in order to let more light reach the image sensor. Or, suppose you are shooting through a telephoto lens. Here, the further away your subject, the more pronounced the effects of camera shake. Both situations require image stabilization to minimize blur.

Image stabilization comes in a few formats. The first is called optical IS, and is often found in moderately-priced cameras designed for novices. The feature relies on a component called a gyro sensor to monitor your movement, and transmit the data to a computer chip. A charge-coupled device (CCD) captures the image after taking this data into account. Optical image stabilization is very effective for maximizing the clarity of your shots. This is largely because you can avoid increasing your ISO setting in low-light circumstances (a higher ISO setting introduces noise).

Another type of image stabilization is digital IS. Here, software is the driving force, rather than a gyro sensor. Cameras with this type of IS boost the ISO setting, which allows you to use a faster shutter speed. As described earlier, this helps reduce blur caused by camera shake.

The downside to digital IS is that it increases ISO past the normal setting for any given light condition. The image sensor is thus made more sensitive than it should be to light. As a result, your images will display noise, which will reduce their clarity.

A third form of image stabilization is dual IS. It blends elements of the previous two types. A gyro sensor monitors your movement, and filters the information to a microchip; software in the camera increases ISO to allow for faster shutter speeds. Some cameras offer duel IS with an added feature that lets you manually override the software's ISO settings.

How can you minimize blur in your images when your camera lacks any type of image stabilization feature? First, whenever possible, use a tripod. Second, if you do not have access to a tripod, shoot while holding your camera with both hands, and keeping your elbows tucked at your sides. Third, lean against a solid object, such as a wall, tree, or door frame. Fourth, synchronize your breathing with your shot so you can avoid inhaling or exhaling when you press the shutter release button.

Image stabilization can be a valuable feature in certain light conditions. Realize, however, it is not a panacea for blur or poor composition.