Image stabilization systems are one of the most highly touted features of consumer digital cameras in the last couple years. They come under many different names and implementations, but all of them perform the same function: Correction of small camera movements to allow blur-free photos that would otherwise require a tripod.

Although in this article I will refer to these systems as image stabilization (or simply IS), that is the name chosen by Canon for use in their product lines and I am using it just for consistency. Other IS producing companies put their own names on their systems including Nikon's Vibration Reduction (VR), Sony's SteadyShot, Sigma's Optical Stabilization (OS), and Panasonic's Optical Image Stabilization (O.I.S) among others.

Image stabilization systems function by altering the path light takes as it travels to the camera's sensor (or film) by either shifting a glass element inside the lens (Canon IS, most Nikon VR), shifting the platform which the digital sensor rests on inside the camera (Sony SteadyShot) or digitally without any moving parts (Fuji, Casio, some Nikon VR equipped cameras).

The last IS method mentioned uses no moving parts and works by digitally sharpening the photo, boosting the light sensitivity (ISO) or by controlling exact area of the sensor being used for recording the image to correct shake. Both these systems are greatly inferior to physical systems as they are generally nowhere near as effective and in most cases alter the photographic image rather than correcting it before it is recorded. Unfortunately camera manufacturers rarely specify whether their cameras use a digital-only system on their packaging, which can be very misleading to a potential buyer. Hardware methods have drawbacks as well, such as higher prices, potential hardware failure, and power consumption.

It all comes down to two simple things: How effective are image stabilization systems and are they worth having.

There are some very important limitations to IS systems that all buyers should be aware of. Firstly, they can only correct for camera movements and not movements of the subject, which rules out the ability to take sharper images of a fast moving car with IS enabled as only the movements of your holding the camera are corrected and not the movement of the car. The second limitation is they work by allowing you to use slower shutter speeds to produce a sharp photo, this will cause blur in any moving subject if the shutter speed drops too low. Lastly, they will not work on long exposures (1/2 second or longer) as their ability to correct shake cannot handle large movements over time that occur when taking long exposure shots and will produce a blurry image.

Panasonic has added their O.I.S system to all their current cameras. Unfortunately they also have deceptive advertising which in some cases show one person in a poorly lit club taking photos of their dancing friend. An IS system would lower the shutter speed of the camera and prevent a blur-free image.

Most image stabilizer systems must be turned off when used on a tripod. Their systems require the camera to be moving (even if only slightly) to prevent them from getting "confused" and behaving erratically.

Overall, image stabilization is a very nice thing to have as it can help you get sharp photos in lighting that otherwise would be blurry. I simply wouldn't pay a high premium for it or expect maricles.