124 Better Available Light Digital Photography
Image-stabilization lenses
Image stabilization is sweeping the camera world, providing
another way to achieve success in low-light situations. This tech-
nology was originally used by aerial photographers—specifi cally
those working from helicopters—to eliminate vibration from the
aircraft. The camera was attached to a cumbersome gyroscope
that absorbed the helicopter movement. Canon introduced the
technology into lenses in the mid-1990s. A small gyro and com-
puter chip work together—detecting the camera shake, shifting
elements to realign the light rays, producing a sharp image. It’s
possible to take acceptable photographs at a two to four times
slower shutter speed than without image stabilization.
These lenses make our old shutter-speed rule of thumb
obsolete. More and more lenses and camera bodies have a
stabilizing system built into them, eliminating vibration and
motion. The result: sharp photographs in less-than-ideal situa-
tions without the need for tripods or other camera supports.
It’s possible to take sharp photographs at shutter speeds
much slower than imaginable. Our rule of thumb tells us that
a 200 mm lens should be shot at a minimum of 1/200 of a
second. The image stabilization of the lens gave us a three-stop
advantage. The IS designation on Canon lenses signifi es their
image stabilization. Nikon’s nomenclature for this kind of
technology is VR (for vibration reduction), and they offer
a series of VR lenses, including the 24–120 mm f/3.5–f/5.6 G
ED-IF AF-S VR and 70–200 mm f/2.8 G AF-S VR. Barry
feels that this kind of stabilization feature eliminates the need
to use a tripod and provides greater mobility. Joe’s not so
sure. Most image-stabilization technology won’t work when
the camera and lens are tripod mounted, because there isn’t
enough movement for the sensors to activate. Canon lenses
perform fi ne when attached to monopods, however, and some
feature a setting just for that application.Case study: fun in acapulco
Canon’s EF 70–200 mm f/4 L IS USM is a lightweight, compact
L-series telephoto zoom lens with built-in optical image stabili-
zation. Like all L-series lenses, it’s built for pros and sealed
against dust and moisture. It uses the latest generation of Canon’s
Image Stabilizer technology to achieve four shutter-speed steps
of camera-shake correction: Three stops in the fi rst 0.5 second
of engagement, then another stop after 2.5 seconds. You can also
select two different modes: one for more or less stationary sub-
jects, and another for panning.
Joe took the EF 70–200 mm f/4 L IS USM with him on a trip to
Acapulco, Mexico and used it as the only lens for two days. It