Image Stabilization: What, When, and How
Image stabilization (IS) is a group of systems that reduce blurry images due to camera shake during exposure.
This is a common problem in still photography that becomes more severe at slower shutter speeds and longer focal lengths. In addressing this problem, camera manufacturers began developing image stabilization systems in the 1990s. Several systems or combinations of IS are in use today:
- Lens based stabilization system
- In-camera image stabilization system
- Digital image stabilization
- Hybrid system
In this article, we’ll describe each system, the pros and cons of IS, and when and how to use it to achieve greater detail in your photographs.
Camera Shake and Reciprocal Rule
If you shoot at fast shutter speeds and can hold a camera steady, you probably don’t need image stabilization. Even then, if you’re using a DSLR, the flip of the mirror or pressing the shutter button can cause minor shakes that lead to blurring.
The handholding rule for photography, also called the Reciprocal Rule, is to set the shutter speed at or faster than the focal length of the lens. That is, if you’re shooting with a 300-mm lens, the shutter speed should be 1/300 second or faster.
Some IS systems add up to five stops to that rule and allow shooting at a much slower shutter speed. That means, with that 300 mm lens, you might be able to shoot handheld at 1/10 second.
Below, two images of a banana plant illustrate the impact image stabilization can have on your photography.
It’s Camera Shake, Not Subject Movement
Camera manufacturers designed image stabilization to detect and correct camera movement. But it will not reduce the motion blur of the subject.
When capturing wildlife in motion or speedy athletes at a sporting event, IS should be disabled. It won’t help, and the mechanisms that detect camera motion can get confused. And this can lead to a sort of feedback loop where the image stabilization system creates motion blur while it’s trying to eliminate it.
In addition, if you are panning to follow a moving subject, keeping the subject in focus while blurring the background, turn off IS.
If you’re using a tripod, the original approach to shake reduction, turn off your camera’s image stabilization technology. The tripod takes care of IS. Also, you may take it a step further with a remote shutter release. That eliminates the risk of the camera introducing image blur into an otherwise stable image.
In Body vs. Optical Image Stabilization OIS
Optical image stabilization is achieved in the lens. A microprocessor measures the shake or movement of the camera along the optical axis, and a floating lens element compensates for that movement.
The system is custom calibrated for each lens, making the lens more expensive. Plus, with each lens purchased, you’re buying another OIS system.
In-body image stabilization refers to a system employing an image sensor that moves to cancel out camera shake and deliver sharp images.
One of the advantages of in-body stabilization over lens-based is that you purchase the system once. That is, it works with every lens in your backpack.
How Does Optical Image Stabilization Work?
The lens based system of IS centers on a flexible lens element. Tiny measuring devices detect any motion of the camera, and pass that data along to a microprocessor, which produces a counter adjustment to that floating lens element. The element moves in multiple directions to cancel out the camera shake.
Telephoto lenses, up to a point, benefit more from an optical image stabilizer. Even slight shakes are magnified by the narrow field of view.
Also, standard and wide-angle lenses gain the advantages of image stabilization, especially in low light situations. In those low light or low contrast settings, a camera’s autofocus system works more efficiently when the image coming into the camera is stabilized.
How Does In-Camera Image Stabilization Work?
An in-camera system of image stabilization relies on a sensor that shifts to counterbalance the camera shake.
When the camera moves, miniature gyroscopes transfer that data to a mechanism that moves the sensor in a corresponding opposite direction. This action corrects the projection of the image onto the camera’s sensor.
A primary asset of shifting the image sensor to achieve IS is that this system works with any lens, even the older ones that predate image stabilization.
However, there is a downside. As the focal length of the lens increases, in-camera stabilizing becomes increasingly less effective when compared to optical image stabilization.
What is Electronic Image Stabilization (EIS)
Electronic or digital IS accomplishes what the other systems do without the physical mechanisms. For this reason, it is increasingly used on smartphone cameras.
Employing a microprocessor, the camera’s software analyzes the camera shake, compensating for movement and reducing the blur. This is especially important for low light photography or shooting a high dynamic range series of shots where each frame must be precisely aligned.
Electronic image stabilization won’t eliminate blur from a moving subject or severe camera shake. It is designed to minimize blurred images in typical handheld settings.
But again, we point out the disadvantage: with digital stabilization, the image sensor needs to be larger than the normal image area to avoid cropping.
Hybrid Image Stabilization (HIS)
As the name suggests, hybrid IS combines optical IS with electronic IS. The optical stabilizer delivers a stable image to the camera’s sensor, while the electronic stabilization technology adds an increased level of image clarity.
Hybrid stabilization smooths out the jittery video and adds stability to still photography in low light shooting, shooting at slow shutter speed, and capturing multiple exposures for high dynamic range images.
Image Stabilization and Telephoto Lenses
When you’re using sturdy camera support, and in certain controlled environments, image stabilization is not a high priority. The same applies to shooting in bright light at fast shutter speeds.
For telephoto lenses with focal length of 100 mm and up, IS becomes less effective. As focal length increases, there is a corresponding magnification of blur resulting from camera movement. Therefore, with super-telephoto focal lengths of 400 mm and up, the best image stabilization is fast shutter speeds.
Preventing Blurred Images with Fast Shutter Speeds
For those of us not steady enough to hand hold their cameras, a fast shutter speed serves as a form of shake reduction.
Shooting athletic events or wildlife requires a fast shutter speed to stop the action and capture sharp images. And since you’ll probably be using a longer focal length, you have multiple reasons to choose a quick exposure time.
For sporting events, a minimum shutter speed of 1/500 second is minimum. I recommend 1/1000 second or faster. For wildlife, especially birds in flight, 1/1000 second should be your slowest shutter speed. I prefer double or triple that.
One of our articles has more information on capturing motion in your photos.
Those fast exposures may require higher ISO settings, which introduce additional noise into the image. So you’ll have to find a balance between sharper images and higher noise.
What Do You Call Vibration Compensation?
Lens manufacturers have a variety of names and branding phrases for image stabilization. The images below show the lens settings for Nikon, Canon, and Sony.
Here’s a list of the leading brands:
- Nikon: Vibration Reduction – VR
- Canon: Image Stabilization – IS
- Sony: Optical Steady Shot – OSS
- Fuji and Olympus: Optical Image Stabilization – OIS
- Pentax: Shake Reduction – SR
- Sigma: Optical Stabilizer – OS
- Tamron: Vibration Compensation – VC
Know Your IS Modes
Camera and lens manufacturers developed various stabilization modes for different situations.
A normal mode is for most of those situations. Specifically, it’s used for low light and slow shutter speed shooting with standard and wide-angle lenses.
The active mode makes greater adjustments to the angle of the image in relation to the sensor. It’s intended for shooting from a moving vehicle.
Sports mode sets image stabilization to the minimum. It’s most useful for shooting on a monopod.
Check your camera’s owners manual to see if it offers these modes or assigns them by different names.
Image Stabilization Points to Remember
IS is not perfect. But technology continues to develop. It won’t make every image tack sharp. And for now, it hasn’t replaced the tripod.
Image stabilization is designed to accommodate shooting still subjects at longer shutter speeds. As we have noted, it does not help you capture quick and erratic moving subjects. For that, use a faster shutter speed.
Whatever combination of camera and lens stabilization you use, it’s ineffective at exposures of 1/500 second and faster. Therefore, when you’re shooting sports and wildlife, turn off the stabilizing function.
The rule of turning off IS when using a tripod needs qualification. Some of the newer, high-end lenses and cameras sense when the camera is stabilized externally. So these cameras automatically turn off the image stabilization. Check the owners manual for your camera and lens to make sure.
Your camera’s IS can reduce jittery video; however, it’s no substitute for a good gimbal system, but it can smooth out the choppy look of your video.
Image stabilization goes by many names: vibration reduction, optical stabilization, and optical steady shot are among them. Whatever it’s called, understanding how it works and when to employ it in various shooting situations will help you get the best results from your camera system. In addition, it’s always a good idea to know what you’re paying for and if you really need it. This technology can help you deliver the image quality you and your clients want.
I hope this article brings understanding and helps you improve your skills. The more you know, the better you will be at the art and business of photography.