The Basics of Image Stabilization
Image stabilization technology uses either hardware or software inside the digital camera to minimize the effects of camera shake or vibration. Camera blur is more pronounced with long zoom lenses or when shooting in low-light conditions, where the camera’s shutter speed must be slower to allow more light to reach the camera’s image sensor. With a slower shutter speed, any vibration or shake occurring with the camera is magnified, sometimes causing blurry photos. Even the slightest movement of your hand or arm could cause a slight blur.
Optical IS Digital IS Dual IS
If you don’t have a camera that offers a good image stabilization system, shoot at faster shutter speeds. Try increasing your camera’s ISO setting so that you can shoot at a faster shutter speed in low light if the camera IS setting doesn’t give you the results you want.
Optical IS
For compact digital cameras aimed at beginner and intermediate photographers, optical image stabilization is the preferred IS technology. Optical IS uses hardware corrections to negate camera shake. Each manufacturer specifies a different configuration for implementing optical IS, but most digital cameras that contain optical image stabilization use a gyro sensor built into the camera that measures any movement from the photographer. The gyro sensor sends its measurements through a stabilization microchip to the CCD, which shifts slightly to compensate. The CCD, or charge-coupled device, records the image.
Digital IS
Digital image stabilization only involves using software and digital camera settings to minimize the effects of camera shake. Essentially, digital IS increases the ISO sensitivity, which is the measurement of the camera’s sensitivity to light. With the camera creating an image from less light, the camera can shoot at a faster shutter speed, which minimizes blur from camera shake. However, digital IS often overrides the ISO sensitivity beyond what the automatic setting on the camera says it should be for the lighting conditions of a particular shot. Increasing the ISO sensitivity in that manner can degrade the image quality, causing more noise in the image—noise is any number of stray pixels that don’t record properly. In other words, asking the camera to try to create an image at less-than-optimal ISO settings could compromise image quality, and that’s what digital IS does. Some cameras also refer to digital image stabilization to describe a piece of software built into the digital camera that tries to minimize the blur after you take the photo, similar to what you could do with an image-editing software on your computer. This type of digital IS is the least effective among all types of image stabilization, however.
Dual IS
Dual IS isn’t quite as easy to pin down, as manufacturers define it differently. The most common definition of dual image stabilization involves a combination of hardware stabilization (as found with optical IS) and increased ISO sensitivity (as found with digital IS). Sometimes, dual image stabilization is used to describe the fact that a digital single-lens reflex camera contains image stabilization technology in both the camera body and in its interchangeable lenses.
Working Without IS
Some older digital cameras don’t offer any type of IS. To prevent camera shake in a digital camera that doesn’t offer image stabilization, try these tips:
Mount your camera on a tripod. Use the camera’s viewfinder, rather than the LCD, to frame the shot. Steady yourself as you shoot by leaning against a wall or door frame. Brace your elbows against the side of your body and hold the camera with two hands. Shoot at a fast shutter speed all of the time, which isn’t always a practical option.
Don’t Be Fooled
Some manufacturers, especially those with low-priced models, use misleading terms, such as anti-blur mode or anti-shake technology, to try to hide the fact that their digital camera doesn’t offer IS. Such cameras usually just increase the shutter speed to limit blurry photos, which sometimes causes other exposure problems, thus harming image quality. Some digital camera manufacturers apply specific brand names for optical image stabilization, further complicating things for the consumer. For example, Nikon sometimes uses Vibration Reduction, and Sony sometimes uses Super Steady Shot to refer to optical IS. Canon created a type of image stabilization that it often refers to as Intelligent IS. Most modern digital cameras either only include optical IS or include some form of dual IS, so finding the right camera to meet your image stabilization needs isn’t as significant of a concern as it may have been several years ago. Still, having a good image stabilization system is so important to your digital camera’s success that it’s worth double-checking your camera has the best type of IS. Don’t forget to check the camera’s specification list for the type of image stabilization that’s available.
