Image stabilization is one of the most misunderstood technologies in the camera industry and yet it is one of the most useful. In short, it allows the photographer to take photographs without “camera shake” with lower shutter speeds.
Before I begin to explain the effects of image stabilization there are 2 important subjects I need to touch on.
One, as a rule of thumb your shutter speed should never drop below the length of the lens and never below 60/s when handheld. For example, on a full frame sensor and assuming your lens is at 100mm, your shutter speed should never fall below 100/s. On most modern cameras this is not true though, you will need to add in the crop factor. For example, at 100mm and you have a Nikon or SONY it would be 150/s (x1.5), a Canon 160/s (x 1.6) and so on. Check your camera’s manual for your crop factor.
Two, there are different image stabilization technologies. Canon has IS (image stabilization) and Nikon’s is VR (vibration reduction) they both use in lens technology, however it can be done in camera as well such as SONY’s SteadyShot. There are advantages of having it in camera, all your lenses will be image stabilized. In recent years we have seen more lenses being stabilized because of in camera video, even fixed (or prime) lenses are now developed with this function in mind.
What is “camera shake”? Have you ever taken a photograph at night and all you see is streaks and waves?
This is caused by not using a tripod when doing long exposures or being below 60/s, let me elaborate, as we take photos we move, breathing, muscle movement, wind… That causes the camera to move along with us, the results are camera shakes this results in blurred photographs, this is where image stabilization becomes useful. Image stabilization compensates for your movements, allowing us to shoot at lower stutter speeds and in lower light. How far lower depends on the image stabilization technology of the lens or camera but it is fair to assume that a gain of 2 to 3 stops is common on modern lenses and cameras. Please check your lens or camera manual for details.
There are some limitations to image stabilization, as shown below the leopard’s paws are blurred, this is called motion blur. An image stabilizer will not compensate for subject movement; only higher shutter speed will help with that.
Another recommendation would be to switch of image stabilization if the camera is mounted on a tripod, though modern image stabilization technology will detect when mounted on a tripod, this is to avoid stabilizer hunting and creating artificial shake or vibration.
Lastly, the image stabilizer become useless above about twice the speed/lens length, so in bright light or outdoors with good light it can be switched off to save battery, I will admit I never do it because I forget to put it back on.
Today I will simply recommend that you buy your lenses with optical stabilization built-in.
My favourites are a 24-105mm and 70-200mm lenses but both these are generally expensive, particularly those with fixed apertures (f/2.8 or f/4). Most camera kits come with an 18-55mm, and sometimes with a tele-zoom lens, with image stabilization. So my real pick would be a 55-200mm or above tele-zoom lens with stabilization, these are relatively affordable starting at about $120 (R1000) depending on manufacturer and give a good zoom range on cropped sensors of 82-300mm and above full frame equivalent. For the Canon owners I would recommend the relatively affordable Canon EF-S 55-250mm f/4.5-5.6 IS MK II (88-400 full frame equivalent) at about $300 (R3000) on budget however I came to appreciate the Canon EF 70-300mm f/4.0-5.6 IS USM (112-480 full frame equivalent) even if it’s nearly twice the price.