Gadget Bag: Image Stability

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Olympus E-3

Shooting at fully extended telephoto lengths without a tripod is a recipe for a blurry shot—unless you have image-stabilization technology. With image stabilization, you can get sharp handheld exposures at longer focal lengths and slower shutter speeds.

All true image-stabilization systems work in basically the same way. The system monitors camera movement and triggers a mechanism that shift key components to counteract the movement. In lens-based systems, with which we’re primarily concerned here, lens elements actually move in this process.

The other variation of image stabilization is built into the camera body. These systems work by shifting the image sensor, rather than lens elements, for essentially the same result. Companies like Olympus, Pentax and Sony feature models that utilize this technology, while Panasonic offers it both in lenses and
the camera body.

The Players
As the two biggest manufacturers of cameras and lenses today, both Canon and Nikon have a similar system for correcting camera shake, as do Panasonic, Sigma and Tamron. Although reluctant to discuss the innermost workings of their respective systems, each of these manufacturers is willing to reveal how its individual system works in general.

Sigma 18-200mm ƒ/3.5-6.3 DC OS HSM

Tamron AF28-300mm ƒ/3.5-6.3 XR Di VC

Canon EF-S 18-55mm ƒ/3.5-5.6 IS

Leica D Vario-Elmar 14-150mm ƒ/3.5-5.6 ASPH

Essentially, there’s a system of sensors that pick up any kind of movement on the X (vertical) or Y (horizontal) axes (Tamron incorporates a triaxial—XYZ—solution), which calculates the range of movement and tells a floating correcting lens element or elements to adjust. The path of light is corrected before it contacts the sensor, counteracting the effects of your movement.

Nikon has Vibration Reduction (VR); Canon offers Image Stabilizer (IS); Panasonic features MEGA Optical Image Stabilization (MEGA O.I.S.); Tamron’s solution is called Vibration Compensation (VC); and Sigma has its Optical Stabilizer (OS) system.

Panasonic Lumix DMC-L10

Sony Alpha DSLR-A700

Pentax K1

Canon
Canon’s approach to its Image Stabilizer technology began in 1995 with the introduction of its first 75-300mm IS lens for SLRs. Since then. the goal has been to create a perfectly clear image when the shutter is snapped and a stable viewfinder image to make composition easier when taking a shot at slower shutter speeds.

The Canon Image Stabilizer system is composed of sensors, actuators (a device for controlling or moving a mechanism) and an optical-correction system. The system works with a set of two vibration gyros and a microcomputer to detect movement. Canon's IS system moves the IS lens to compensate for shake by shifting the position of the lens, creating a clear exposure. Note, also, that Canon IS has a Mode 1 and Mode 2. Mode 1 uses both the X and Y axes when the IS is on, but when Mode 2 is utilized (best for panning a continuously moving subject), the X axis isn’t compensated for.

The newest IS lens from Canon is its EF-S 18-55mm ƒ/3.5-5.6 IS standard zoom lens. This wide-angle lens lets you shoot handheld at up to four stops slower with IS enabled. Canon’s offering of IS lenses includes standard zooms, telephoto and super-telephoto zoom lenses.

Nikon
Nikon’s VR lens system is controlled by two sensors that use the physics theory of angular momentum, which states an object rotating (the VR lens) will continue to rotate at the same point unless it’s acted upon by an external force—in this case, a Voice Coil Motor system that detects movements on the vertical and horizontal axes to compensate for shake. So every 1/1000th of a second, the angular velocity is examined, and the data is sent to a microcomputer in the lens that calculates the amount of compensation that’s needed.

To compensate for different shooting scenarios, Nikon has two modes for the new VR II lens system. The first is Normal Mode, in which only slow or wide camera movements are compensated for. The second, Active Mode, anticipates some camera movement, such as panning the camera, and corrects only for unwanted vertical movements.

The new Nikon AF-S Nikkor 400mm ƒ/2.8G ED VR telephoto lens incorporates this second generation
of Vibration Reduction technology, which lets you use up to four shutter speeds slower than you could normally shoot handheld. This new super-telephoto lens has a fixed maximum aperture of ƒ/2.8, allowing for a shallow depth of field.

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AF-S Nikkor 400mm ƒ/2.8G ED VR

The 400mm also has a Silent Wave Motor (SWM) that lets you focus instantly, even at fully extended focal ranges. If you plan to shoot with a tripod, the lens has a VR on/off switch to disable stabilization, as well as a cool feature called Tripod Detection that counters the effect of VR when the lens is already stabilized on a tripod. Other specs include a 10.2-pound weight, minimum focusing distance of 9.5 feet and a minimum aperture of ƒ/22. Nikon also has a variety of other VR lenses in its stable, including telephotos, super-telephotos and standard zoom lenses, giving you a variety of glass with this effective system.

Panasonic
Panasonic is unique in that it utilizes its MEGA Optical Image Stabilization (MEGA O.I.S.) both in the camera body and in interchangeable lenses. As Panasonic released its first-ever D-SLR, the Lumix DMC-L1, and now its most recent D-SLR, the Lumix DMC-L10, it formed a partnership with Leica to provide interchangeable lenses with IS.

The most integral part of the MEGA O.I.S. is a gyro sensor that detects any sort of shake. The movement sends a signal to a microcomputer inside the camera that calculates the amount of compensation that’s needed. A linear motor sends a signal back to the optical image stabilizer that moves the stabilizer to the correct path of light as it hits the image sensor.

The MEGA O.I.S. has three modes. In Mode 1, image stabilization is constantly on, so framing is always stabilized through the lens as well. Mode 2 turns on stabilization only when the shutter is pressed, which gives clearer pictures without slowing down the camera. And finally, Mode 3 compensates only for up-and-down movements, not horizontal-axis movements, which helps capture fast-moving subjects when you're panning or want blur for creative effect.

The newest lens from Panasonic is the Leica D Vario-Elmar 14-150mm ƒ/3.5-5.6 ASPH lens. With a 20-inch minimum focusing distance, it also features a new technology called Extra Silent Motor (XSM) that has a supersonic oscillation engine that increases responsiveness and focusing to the camera.

Sigma
Sigma’s OS (Optical Stabilizer) system is similar to most of the systems mentioned above. Because all image stabilization technology is about letting the photographer shoot handheld, Sigma’s technology is made to address low light and eliminate blur at long focal ranges.

The OS system uses a group of lens elements that are controlled by two sensors inside the lens, which detect both vertical and horizontal movement. The elements move to correct themselves as the other systems do, and also have two optical stabilizer modes. Mode 1 detects vertical and horizontal movement. Mode 2 detects only on the vertical axis, making it useful for catching moving subjects while panning the camera.

Sigma’s latest lens is the 18-200mm ƒ/3.5-6.3 DC OS HSM lens for Nikon-mount cameras, good for macro to telephoto shooting, with a minimum focusing distance of 17.7 inches. Sigma also manufactures two other lenses with its OS technology, the 80-400mm ƒ/4.5-5.6 EX DG OS and another 18-200mm without HSM (Hyper-Sonic Motor) autofocus.

Tamron
Tamron is the newest kid on the block to offer an interchangeable zoom lens with optical stabilization, which it has named Vibration Compensation (VC). The VC system works by featuring a triaxial (X=horizontal, Y=vertical, Z=curvelike movements on both X and Y axes) configuration of driving coils and sliding balls to compensate for hand shake. Three driving coils move the VC lens through electromagnetic signals originating from the movement of the steel balls. The lens element that compensates for movement is held in place by these steel balls, which is controlled electronically to operate a mechanical system that holds the lens in place to get a clear shot.

Tamron’s first VC lens is the AF28-300mm ƒ/3.5-6.3 XR Di VC LD Aspherical (IF) macro zoom lens. The 28-300mm has a maximum aperture of ƒ/3.5-6.3 and a minimum aperture of ƒ/40. The new lens fits on both Canon AF and Nikon AF-D camera bodies.