Image stabilization, or vibration reduction, O.I.S., Optical SteadyShot, SR, VC, VR, MEGA O.I.S., and other equally catchy monikers, are technologies that enable photographers to take pictures under lighting conditions that once upon a time would have been considered too iffy for capturing sharp still images. Depending on the make, model, and vintage of your IS-enabled camera or lens, image stabilization allows you to capture sharp pictures at shutter speeds three, four, or five times slower than previously possible.
The rule of thumb for capturing sharp, handheld imagery is that you shouldn’t handhold a camera at shutter speeds slower than the equivalent focal length of the lens. This means a 500mm lens shouldn’t be handheld at speeds slower than 1/500-second, a 300mm lens slower than 1/300-second, a 50mm lens slower than 1/50-second, and a 20mm lens slower than 1/20-second.
Add image stabilization into the mix and suddenly you can capture sharp images of still objects with a 500mm lens at speeds down to 1/60-second, a 300mm lens at speeds down to 1/30-second, and a 20mm lens at speeds down to 1/2-second.
The problem is that, while setting up a new camera for the first time, many shooters turn the camera or lens’s image stabilization on and never look back, figuring “If I need it, it’s on,” but depending on your particular camera or lens, that may or may not be such a good idea.
Before getting into the nitty-gritty of the subject, it’s important to clarify a common misconception about image stabilization, which is that it enables you to “freeze” fast-moving objects at slower shutter speeds. This is totally false. Image stabilization only allows you the ability to capture sharp images of static subjects at slower speeds. Moving objects will be equally blurry or streaky—and in some cases blurrier or shakier with the IS turned on.
Lens-based stabilization: Camera and lens system when still
There are two types of image stabilization (IS): lens based and in camera. Lens-based stabilization uses a floating lens element, which is electronically controlled and shifted opposite to any camera shake recorded by the camera. In-camera systems work similarly, but will physically shift the image sensor to compensate for these movements. As for which form of image stabilization is better, there are pros and cons for both sides.
Lens-based stabilization: Camera and lens system jerked downwards, producing camera shake
The advantages of in-lens image stabilization include smoother performance when using longer focal length lenses. The downside of lens-based image stabilization is that it’s not available as an option for all lenses and it adds to the cost of the lens. Then again, if you don’t need IS, you often have the option of purchasing a non-IS version of the lens, or at least something similar.
Lens-based stabilization: Correction made by IS lens group
The pros of in-camera image stabilization are that you gain the advantages of IS technology with any lens you can mount on the camera for considerably less cost than multiple IS-enabled optics. The downside of in-camera image stabilization is that it’s less effective at smoothing the bumps when shooting with longer focal length optics when compared to lens-based image stabilization.
Camera-based stabilization: Camera and lens system when still
If you mount the camera on a tripod (or similar stable platform) without cutting the IS, you risk creating what’s called a feedback loop, in which the camera’s IS system essentially detects its own vibrations and starts moving around, even when the rest of the camera is completely still. This introduces motion objects to your camera system and brings with it blurriness. This is one of the key reasons to turn off image stabilization.
Camera-based stabilization: Camera and lens system jerked downwards, producing camera shake
Many systems feature specialized modes for panning action and this should be used when shooting action and other subjects that require constant side-to-side motion. However, some older lenses and entry-level systems may not have this option, or may not operate properly when panning, resulting in more blurring. This is an instance when it may be beneficial to turn your stabilization system off.
Lens-based stabilization: Sensor shift ameliorates camera shake
Also, another reason one could come up with to shut down their stabilization system is battery life. Electronically controlled and measured, IS will eat up battery power. This is especially true with larger lenses and larger sensors, which inherently require more energy to move around.
On a final note: it is well worth mentioning that, for the sharpest results when photographing still subjects, nothing beats a camera mounted on a sturdy tripod with the image stabilization turned off. This is because image stabilization, by its very nature, using motion along one axis to counter motion in the opposite axis, often creates varying degrees of image degradation of its own, whereas a camera firmly coupled to a stable tripod and tripped with a cable or remote release with the mirror locked in the up position will, in almost every instance, take a sharper picture.
