A camera that shakes can make watching a video feel like you just got off a Russian mountain, but without the excitement of turns and falls. And in a photo it can reduce the sharpness and obscure details. The image stabilizer can help counteract the shake of a long lens, hand tremors or even moving motion.
Image stabilization has become an essential feature of mirrorless cameras and action cameras; DSLR types, with the exception of Pentax, do not usually include image stabilization within the body, preferring lens stabilization.
Why do you need image stabilization?
Image stabilization fights camera movement to create stronger photographs and more stable videos. A camera that uses it can shoot at much lower speeds, creating a cleaner and clearer photo in low light conditions than with the alternative of raising the ISO, as this produces noise. The reciprocity rule suggests that a 100mm lens should not be used to shoot at speeds less than 1/100 of a second; but with stabilization you can lower the speed even more. That allows you to take pictures in low light or wear long lenses without a tripod.
Stabilization also helps in small but important ways. Stabilize what you see through the viewfinder before you take the picture, helping you keep the frame. In addition, it helps the autofocus system, keeping the main element of the composition stable under the same focus points.
What is optical image stabilization?
This is the type of stabilization that occurs while capturing the photo or video, not later, through parts inside the lens or the camera body. This system has a mechanical component, as there are physical parts inside a lens or camera that move to compensate for the shock.
There are two types of optical image stabilization. Traditionally, it was incorporated into the lens, and that is still common. A gyroscope reads the movement of the camera and certain elements move in response, obtaining a more stable image.
Optical stabilization can also be found inside the camera body. The sensor shift stabilization uses a gyroscope to move the sensor, instead of a lens element. Sensor stabilization is usually more convenient because any lens can be stabilized. Lenses with stabilization are usually more expensive, so working with a stabilized body can be more cost effective than acquiring several stabilized lenses.
In some systems, stabilization in the body and lens can be combined, resulting in even more stabilizing power. However, a system in the lens usually works better in long lenses, as it can be optimized for its focal length.
Finding a camera with image stabilization in the body is simple: you only need to consult the specifications (it may be abbreviated as IBIS, for its acronym in English).
In the case of lenses, each manufacturer has a different name for image stabilization, but if you see any of these denominations in the name of the lens, it has:
- Canon and Olympus IS
- Nikon VR
- Sony OSS
- Fujifilm, Panasonic, Leica OIS
- Sigma OS
- Tamron VC
What is digital stabilization?
Like digital zoom, digital stabilization is less than optical. However, advances in technology have made some digital systems stand out.
Digital stabilization is hardly used for anything other than video. It occurs after the video has been captured, cropping and re-framing the image automatically to obtain a more fluid result, although with a smaller field of view. Whenever a video is clipped, pixels are lost, so the optical stabilization is still superior to the digital one.
However, digital stabilization is improving. GoPro's impressive HyperSmooth system uses scene recognition, and instead of applying a stabilizing algorithm to everything, it analyzes the movement of each scene. The computer trims the image based on that movement and the clipping is only 10 percent. Considering how moved the shots of an action camera are, the video stabilized with HyperSmooth almost always looks better than the original version.
360 cameras have a unique advantage in terms of digital stabilization. Since the camera captures a complete spherical area around it, it has infinite freedom to reframe the active field of view without cropping, resulting in superior stabilization without losing pixels.
Static stabilization vs. digital: which is better?
Unlike optical stabilization, digital stabilization only works with video. This makes optical stabilization the obvious winner when talking about photography. And in most cases, optical stabilization is also superior for making video, because with a system of optical stabilization you don't sacrifice any resolution.
Although optical stabilization can make a body or lens slightly more bulky than similar versions without stabilization, in most cases the benefit of stabilization makes the larger volume worthwhile, particularly when working with long lenses. In low light conditions.
In cameras too small for optical stabilization, digital stabilization is necessary. Although average digital systems are nothing special, GoPro HyperSmooth and DJI Rock Steady are examples of quality digital stabilization.
Why is stabilization measured in steps?
Image stabilization systems are usually three or five axes; This refers to the number of directions in which the system can move to compensate for the jolt. A three-axis system correct the camera's movements in three different ways, while one of five offers the maximum possible stabilization.
But in addition to the amount of motion directions that can be corrected, image stabilization is also measured in steps (or stops). This specification tells you how much you can reduce the shutter speed and still get a sharp shot with the stabilization system. One step, in terms of photography, refers to doubling or halving the amount of light in a capture. For image stabilization, each step refers to the number of times you can divide the shutter speed in two and shoot without a tripod.
For example: if you work with a 125mm lens, the lowest speed with which you can use it is usually 1/125. However, with a five-step stabilization system, you can divide 1/125 into two five times, which means that, theoretically, you can shoot at 1/4 of a second.
The five-step stabilization is excellent, although not the best. Olympus has managed to reach 7.5 steps in its OM-D E-M1X flagship camera by combining it with specific lenses; That allowed us to make a 10-second exhibition without a tripod.