Image Stabilization

What is image stabilization?
Image Stabilization (IS) is also known as anti-shake and vibration reduction. It is a technology found in many digital cameras with long telephoto zooms of 10X and 12X. By image stabilization, images are not blurred. Camera shake, slow shutter speed and the usage of a long telephoto lens without a tripod, causes vibration that makes the image blurred. Image stabilization corrects and reduces this vibration. Image stabilization was developed for video cameras but is nowadays found in interchangeable lens, consumer and professional digital cameras.

Why is image stabilization required?
Image stabilization is required to eliminate vibration and thereby prevent images from being blurred.

Digital cameras and image stabilization
• Digital cameras that feature image stabilization have a built-in gyrosensor and a microprocessor, which detects the camera shake as it occurs.
• If the subject is moving, then blurring may occur which image stabilization cannot prevent.
• With the help of image stabilization, you can take handheld shots two stops slower.
• Image stabilization proves extremely useful when shooting with telephoto lens.
• It is also beneficial when shooting subjects in low light.
• Digital cameras use optical image stabilization.
• Many manufacturers recommend turning off image stabilization when a camera support like a tripod is being used.

How is vibration caused in a digital camera?
• By camera shake - When you take a picture, if your digital camera makes even a slight movement, the chances of obtaining a blurred photo is greatly increased. The most common cause of camera shake in new digital camera users is the incorrect usage of the shutter-release button. The button must not be pressed twice, but pressed two steps down. The first step locks the focus and exposure, and the second step takes the photo. Camera shake requires image stabilization.

• By slow shutter speed - The amount of time when the shutter remains open to allow light to reach the digital camera sensor is known as shutter speed, and is measured in seconds or fractions of a second. A fast shutter speed is used to freeze fast-moving subjects, whereas a slow shutter speed is used to capture the motion of a subject. By the combination of the lens aperture and shutter speed, an image is exposed. A slow shutter speed needs a small aperture (large F-stop number) to avoid over-exposure. With a slow shutter speed, for example when using shutter speed below 1/60th of a second, the digital camera is likely to vibrate more and hence image stabilization is required.

• Not using a tripod when required - A tripod is an essential digital camera accessory as it creates a steady, level platform. This eliminates camera shake caused by digital camera movement and slow shutter speed. It is particularly useful when using long telephoto lens. A tripod is helpful in close-up, panning and landscape shots, for taking photos in low or dim light, for timed exposures and for shooting at slow shutter speed below 1/60th of a second. A tripod is easy to set up and use, and is available in numerous varieties from modular and lightweight to rigid and heavy-duty. When a tripod is not used, where it should be used, then image stabilization is required by a professional digital camera.