Get some Stability in Your Life (Image Stabilization That is)

Image Stabilization
Can Get You Two Stops Less

By and large, using image stabilization can allow you shoot handheld shots around two stops less than without image stabilization. Another way of putting it is if you need a shutter speed of 1/500s to capture an individual scene, you should therefore be able to shoot it with image stabilization only 1/125s (or 4 times slower). This comes in very handy when shooting moving targets in poor light environments, when panning or when employing long focal lengths.

Waterfall Stabilization Comparisons
An image that compares two shots of a waterfall. The left image has Optical Image Stabilization enabled, while the right image has Stabilization turned off.

Many telephoto lenses designed for DSLR cameras often come with equipped image stabilization. Stabilization is also offered in video digital cameras with long zoom lenses. Digital cameras with long zoom lenses also have integrated image stabilization or other variants much the same as anti-shake features. Stabilization helps with steadying the image being sent back to the sensor by using a "floating" optical component often attached to a fast spinning gyroscope that assists in counterbalancing high frequency vibration, for example (hand shake) at these extended focal lengths. There is an IS suffix after the name on Canon EF lenses using image stabilization, VR "Vibration Reduction" is used on Nikkor lenses image stabilized lenses.

Still Photography Application

Image stabilization In photography, can many times allow using shutter speeds 3-4 stops slower (8-6 times longer exposure time), although even slower successful speeds have been accounted.

A general rule of thumb to figure out the slowest possible shutter speed for hand-holding the camera without noticeable shake blur is to use the reciprocal of the equivalent 35mm lens focal length. For instance, using a focal length of 125 mm, camera shake or vibration could influence sharpness for example shutter speed was reduced to less than 1/125 second. Resulting in 3-4 stops allowable slower shutter speeds by Image Stabilization, a photo shot at 1/125 second speed with an normal lens could be shot at 1/15 or 1/8 second using a Stabilized lens and generate almost identical quality. The amount of sharpness reachable at a given speed can increase significantly. When figuring the effective focal length, it's imperative to take the camera's image format into account. For example, a large number DSLR models use an APS-C sensor. Multipliers 1.5 or 1.6, are used to obtain the len's effective focal length, depending on the model. The resulting value is labeled as focal-length multiplier, format factor, crop factor, or field-of-view crop factor.

In any case, image stabilization technology does not stop motion blur initiated by subject movement or by extreme camera movements. Image stabilization was designed for and only capable of reducing resulting blur caused from everyday, minor lens shake during shooting hand-held. Some lenses include a more assertive 'active mode' or a secondary panning function or, both which are described in more detail below under the title "optical image stabilization".

Techniques of image stabilization

Optical Image Stabilization

The Optical Image Stabilizer, most often shortened to OIS or just OS, is a device used in a both still and video cameras that stabilizes the captured photo by fluctuating the optical path to the image sensor. This expertise is put into operation inside the lens itself instead of inside the camera, as some of the other method laid out below. The principal reason inserting in the lens is to avoid inserting glass lenses inside the body of the camera which would dramatically increase its size, and by placing IS inside the lens itself allows the technique to be tweaked for the uniqueness of each particular lens.

VC Diagram

Different manufactures use distinctive names for their OIS technology; for instance: (Canon- IS) Image Stabilization, the first to create an OIS lens), (Nikon- VR) Vibration Reduction, (Panasonic and Leica) MegaOIS, (Sony- SSS) Super Steady Shot, (Sigma - OS) Optical Stabilization, (Tamron- VC) Vibration Compensation and (Pentax- SR) Shake Reduction.

In Nikon and Canon's technology, it works by employing a floating lens element that is shifted orthogonally to the lens optical axis employing electromagnets. Vibration is sensed by using a pair of piezoelectric angular velocity sensors (many times called gyroscopic sensors), one sensor to detect horizontal transfer and the other sensor to detect vertical transfer. This results, this kind of stabilizer is only able correct for rotations of axis pitch and yaw, and is not able to correct for optical axis rotation. A few lenses feature a secondary function that thwarts vertical camera shake only. The latter mode is effective when applying a panning technique, and changing into this mode varies by the lens in use; sometimes it can be automatic. or other times by moving a switch on the lens

Some of the more recent VR-featured lenses from Nikon include an 'Active Mode' that has the capacity to be employed when capturing images from a moving car or boat, and theoretically correct for more intense shakes than when the 'Normal Mode'. Having said thar, Active Mode, when employed for normal shooting environments, can often result in poorer images than the 'Normal Mode'.

Developed using Sigma's own in-house technology, the Optical Stabilizer (OS) feature employs double sensors within the lens to distinguish for both horizontal and vertical camera movements. This feature, operates by repositioning an optical image stabilizing lens cluster, to effectively counterweigh for camera shake, goes a long way in setting Sigma lenses apart from others. To handle various types of shooting environments, the system has not one, but two optical stabilizer modes. Mode 1 reveals camera shake when horizontal and vertical panning and counterweighs for image blurring. For that reason it is effective for shooting general images or for capturing landscapes or other static targets. Mode 2 reveals vertical camera shake and counterweighs for blurring. It is for that reason effective for sweeping the camera to capture moving targets such as auto racing.

Tamron’s exclusive tri-axial Vibration Compensation (VC) technology minimizes the results of shake from hand holding the camera. Tamron’s stabilization technology manages the results of camera shake in three definite planes. VC allows more occasions for precise hand-held shooting (up to 4-stops) using slower shutter speeds required when shooting in poor light environments (e.g. indoor or night locations) spectacularly enhancing the photographer’s level of photographic independence. The Tamron VC includes a tri-axial arrangement employing three pairs of driving coils and slide balls about the optical system compensator lens group' . As the compensator lenses are sustained with rolling friction of the balls, the reaction performance is improved and the manufacture is simple,

Almost all lens makers suggest turning off the IS function on the lens when being tripod mounted as it may cause erratic consequences and is normally not necessary. Many of today's image stabilized lenses (notably Canon's recent IS lenses) have the ability to auto-detect when installed on a tripod (This is sensed by a exceptionally low vibration reading) and IS is disabled automatically to prevent any consequent reduction in image. IS also draws battery power, so de-activating IS when unneeded will extend battery life prior a recharge being needed. 

Moving the image sensor

The sensor acquiring the image can be shifted in ways to counteract the camera motion, a technology often called mechanical image stabilization. As the camera rotates, creating positional error, gyroscopes encode details to the actuator that shifts the sensor. The image sensor is then moved to preserve the showing of the image onto the image plane, being a feature of the focal length of the lens that is being employed; Today's newer cameras can obtain focal length details from the mounted lens. SteadyShot is used in Sony's a models and "shake reduction - SR" used in Pentax the K10D and Pentax K100D models, which depends on a very accurate angle speed sensor to notice camera motion. Olympus initiated image stabilization on their E-510 DSLR camera body, using a system constructed around the Supersonic Wave Drive. Several other lens makers employ DSPs to dynamically evaluate the image and subsequently shift the sensor by an appropriate amount. Sensor moving is also employed on several cameras manufactured by Casio Exilim, Pentax, Fujifilm, Samsung, and Ricoh Caplio.

The advantages from shift the image sensor, and not the lens, results in stabilized image no matter what lens is mounted. This results in less expensive lenses for this type of camera, plus the lenses are lighter.

The single big disadvantage from shifting the image sensor is that the image sent to the viewfinder is un-stabilized. Conversely, this is not a problem with cameras that employ an electronic viewfinder (EVF), as the image projected to that viewfinder is obtained from the image sensor


Digital image stabilization

Digital image stabilization is employed in a few video cameras. The technique moves the image electronically from frame to frame of the video, just enough to offset the motion. It employs pixels beyond the frame border that is visible to make a buffer available for the motion.

Stabilization filters

A number of non-linear editing techniques employ stabilization filters which can fix a non-stabilized picture by tracking the image pixel movement and repairing the image by shifting the frame. The procedure resembles digital image stabilization except no "larger" image exists to control, the filter then either crops the image to conceal the frame motion or makes an attempt to recreate the displaced image at the outer edge using extrapolation.

Orthogonal Transfer CCD

An orthogonal transfer CCD (OTCCD), employed in astronomy, actually moves the image from inside the CCD itself as the picture is being acquired, based on examination of the perceptible movement of brilliant stars. This is an odd case in point for digital stabilization of still images. An example is available with the upcoming Pan-STARRS gigapixel telescope under construction in Hawaii.

Stabilizing the camera body

A method that needs no added resources of any camera with lens combination is created by externally stabilizing the camera body instead of employing an internal approach. This is pulled off by append a gyroscope to the body of the camera, most often using the camera's tripod mount. This permits an external gyro to stabilize the camera, and is normally employed in shooting images from a moving vehicle, when a camera or lens providing some other type of image stabilization is unavailable.

Sensor-shift image-stabilization

Sensor-shift image-stabilization system is one of three in-camera automated solutions created to reduce or eliminate the consequences of camera shake when using long exposures. The two others are optical image stabilization (OIS) and electronic or digital image stabilization. The Sensor-shift image-stabilization system is perhaps the best of the three and here is why.

The Sensor-shift image-stabilization system operates by moving the sensor of the camera around the image plane by using electrical actuators. If any shake motion is encountered by the camera’s accelerometers, it calculates the direction and speed in real time to move the sensor, so that it remains motionless in relation to the image projected onto it by the lens. The effectiveness is limited, just like any image-stabilization system, but it can be useful in somewhat low-light environments when a tripod or other support is unavailable.

The benefits over other systems are that the sensor-shift image-stabilization system operates with any lens mounted to the camera (just as long as the camera knows the lens focal length), not only lenses fitted with optical image stabilization, and there is nominal compromise of optical image quality. The newer sensor-shift image-stabilization systems operate in up to five axes to adjust camera movement up and down, left and right, including camera rotation.

The Sensor-shift image-stabilization system is installed in Olympus and Pentax cameras, along with several Sony and Panasonic cameras. Pentax uses it for some cool features on some of its cameras, like the ability to move the sensor during extremely long exposures as a way to keep stars focused as they move across the night sky. Olympus features one on the OM-D E-M5 Mark II as a way to create 40MP high-resolution composite images, too.

One other method to stabilize a video/motion picture camera is the Steadicam which detaches the body of the operator from the camera by employing a camera boom and a counterweight with harness.

updated article Updated March 30, 2016 -

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