Understanding Optical and Digital Image Stabilization

Many camcorders and even some higher-end smartphones include some form of image stabilization technology to reduce the video blur that results from shaky hands or body movement.

Image stabilization is important for all camcorders, but it's particularly crucial in those that have slow shutter speeds or long optical zoom lenses. When a lens is zoomed out to its maximum magnification, it becomes sensitive to even the slightest motion.

Some manufacturers put a brand name on their image stabilization technology. Sony dubs it SteadyShot while Panasonic calls their Mega O.I.S and Pentax Shake Reduction. Each approach presents nuances but they perform the same basic function.

Optical Image Stabilization

Optical image stabilization is the most effective form of image stabilization. Camcorders with optical image stabilization typically feature tiny gyro-sensors inside the lens that quickly shift pieces of the lens glass to the off-set motion before the image is converted to a digital form.

An image stabilization technology is considered optical if it features a moving element inside the lens.

Some camcorder manufacturers let you turn optical image stabilization on and off, or include several modes to compensate for different kinds of camera movement (either vertical or horizontal).

Digital Image Stabilization

Unlike optical systems, digital image stabilization — also called electronic image stabilization — uses software to reduce blur.

Some camcorders calculate the effect of your body movement and use that data to adjust which pixels on the camcorder's image sensor activate. It uses pixels from beyond the visible frame as a motion buffer to smooth over the transition frame by frame.

For consumer digital camcorders, digital image stabilization is usually less effective than optical stabilization. It, therefore, pays to look closely when a camcorder claims to have "image stabilization." It might only be of the digital variety.

Some software programs apply a stabilization filter to the video even after it's been taken, by tracking the pixel movements and adjusting the frame. However, this technique results in either a smaller cropped image or extrapolation to fill in the lost edges.

Other Image Stabilization Technologies

Although optical and digital stabilization is most common, other technologies attempt to fix unstable video, too.

For example, external systems stabilize the entire camera body. A gyroscope attached to the body of the camera stabilizes the entire rig. Professional videographers use tools like this, which are often casually referred to as a 'steadicam rig,' though, technically, Steadicam is a name brand that creates various stabilizers.

And don't forget the most common and easy-to-use method of stabilization: your trusty tripod.