What is Canon Image Stabilization?
Canon image stabilization technology, many times referred to as "IS," is a feature found on many of the lenses in Canon's lineup. Many photography novices or recent film to digital converts wonder if IS actually provides better results. This is a good question as Canon IS technology adds weight, size, and increases the price of almost every lens it is included as a feature on. This article is going to look at the advantages of Canon image stabilization in light of these downsides.
How does Canon IS work?
Canon's IS system works with an optical image stabilizer. The stabilizer is an extra floating optical element that is added to existing lens optics. It is designed to detect lens movement and correct for it by altering the path light takes through the optical elements of the lens on its way to the digital image sensor. A series of electromagnets help perform this task. As the movement sensor only detects when the lens moves, and the floating element can only correct for lens motion, IS only works to reduce blur in image subjects that are not in motion. In other words, Canon image stabilization cannot freeze the motion of a moving object in low light conditions, it can only reduce (or eliminate) the effects of camera shake when hand holding at low shutter speeds.
Is Canon IS really it?
Many photographers find Canon IS to be an invaluable tool in many different lighting conditions. Most Canon lenses equipped with IS allow for excellent results in hand held (non-tripod) photography while shooting 2-3 stops lower than lenses without IS. Some Canon lenses with IS will work 4 stops lower than normal. Furthermore, under the lowest of light conditions and while hand holding, some users have noticed that consumer grade Canon IS lenses outperform some of the much more expensive (and sought after) "L Series" lenses that do not have image stabilization. Canon image stabilization definitely improves results while hand holding.
Canon does offer a few recommendations for use of IS. First, you do not need to use it when your lens is mounted on a tripod. Canon actually recommends that you disable IS when tripod shooting to avoid image distorting effects.
Second, the IS feature requires extra power and can drain your camera battery quickly. Therefore, it is best to turn it off when not shooting in low light conditions.