Canon EF Lenses

Canon EF-S 17-55mm f/2.8 IS USM Zoom Lens

The Canon EF-S 17-55mm f/2.8 IS USM offers image quality on a par with Canon's highly regarded L-series lenses. It has a large maximum aperture which, combined with higher shutter speeds can minimize subject motion blur. Shallow depth-of-field separation of a subject from its background is much easier to achieve and the f/2.8 maximum aperture allows a bright finder and extremely precise focusing with f/2.8 compatible AF sensors.

The internal stabilization has a sharpness benefit equivalent to a three-stop faster shutter speed, making this lens outstanding in low light situations. Smaller and lighter than lenses of similar specifications, the EF-S 17-55 mm f/2.8 IS USM lens has a 35mm equivalent focal length of 27-88mm and is compatible only with the EOS 30D, EOS 20D, EOS Digital Rebel XT and EOS Digital Rebel SLRs.

Canon EF-S 17-55mm f/2.8 IS USM

Features and Specs | Large Image

Key Features of the Canon EF-S 17-55mm f/2.8 IS USM Zoom Lens

Image Stabilization Technology: Canon has developed a series of truly unique lenses equipped with an Image Stabilizer (IS) function that let you capture photos that would otherwise be blurred due to camera movement, greatly expanding the range of handheld-camera photography. In many shooting situations where photographers are not allowed to use a tripod or flash, such as art museums and concert halls, Canon IS lenses are your ticket to sharper pictures.
Blurred pictures due to camera shake become more of a problem when taking pictures in dim light - at dusk, indoors, on a cloudy day. And the chance of getting blurred pictures is greater when using longer focal length lenses that magnify the image and any associated movement. To overcome these problems, Canon developed the world's first SLR lens with a built-in image stabilizer. Electronic signals emitted by vibration-detecting gyro sensors are used to move the image-stabilizing lens group in parallel along the optical axis, providing clear picture quality at all times. Actual shooting tests result in improvement equivalent to using a shutter speed three steps faster.
17-55mm Zoom Range: Compact and lightweight wide zoom lens specifically for digital SLRs that accept EF-S lenses. Uses optics designed to take full advantage of the small image circle and short back focus in EF-S lenses. 17-55mm (equivalent to a focal length of 27-88mm in 35mm format), 3.2x zoom ratio.
Two Ultra-Low Dispersion UD Glass Lens Elements: The EF-S 17-55mm f/2.8 IS USM is a professional zoom lens with high contrast and high resolving power. It is constructed using the finest optics including two UD (Ultra-Low Dispersion) glass elements designed to correct chromatic aberrations, resulting in extremely sharp images with excellent color rendition.
Ultrasonic Motor: Powered by Canon's exclusive Ultrasonic (USM) motor for autofocusing, the EF-S 17-55mm f/2.8 IS USM is silent in operation and very quick to focus. There is virtually no whining noise as the lens focuses to distract the subject or draw attention to the photographer. Most important for the photographer in the field, the motor draws minimal power so the camera batteries last longer.
Three Aspherical Lens Elements: Wide-angle lenses and fast normal focal-length lenses often suffer from an optical problem -- spherical aberration -- which causes an overall softening and optical "smearing" of the image. Canon has developed four different manufacturing technologies to produce Aspherical lens elements, which combat this problem. Aspherical optics, which have an extremely precise variable curvature of one or both sides of a lens element, also allow more compact lens designs and permit lighter lenses with fewer elements.
Inner Focusing and Rear Focusing: An inner focusing lens has the focusing lens group(s) in front of the diaphragm, while a rear focusing lens has the focusing lens group(s) behind the diaphragm. Both focusing systems allow the focusing lens group to be small. This minimizes the load on the actuator which drives the autofocus. In turn, the AF speed is faster. The whole optical system can also be made more compact. Also, since the lens does not rotate during focusing, the effects of a circular polarizing filter or gelatin filter remain intact.
Full-Time Manual Focus: Ring-type Ultrasonic Motor allows manual focusing without switching out of the auto mode, making this lens ideal for many photographic applications including sports, photojournalism, portraits, and landscapes.
Circular Aperture: This Canon lens features a circular apertures diapragm unit, which uses curved aperture blades to provide for a more rounded opening as the lens is stopped down. It's especially effective at rendering out-of-focus background highlights as natural rounded shapes. Offers a more pleasing out-of-focus image.
Optimized Lens Coating for Digital Cameras: Optimized lens coating minimising flare and ghosting prone occurring with digital cameras.
EF Lens Mount: In designing the EF lens mount, Canon engineers gave photographers a lot more than simply a way to quickly attach an interchangeable lens to a camera body. With the elimination of mechanical connections and the incorporation of an electronic interface between the camera and lens, Canon cameras have greater flexibility with regard to incorporating future technologies and future system upgrades. This fact has already been proven with a vast increase in AF speed, increased functionality such as predictive autofocus systems found in EOS cameras, auto-aperture tilt-shift (TS-E) lenses, the use of ultrasonic motors and the development of the Image Stabilizer lens.
The fully electronic mount system has none of the shock, operational noise, abrasion, play, lubrication requirements, slow response, diminished precision caused by lever operation, or design restrictions related to linkage mechanisms used to transfer data. Furthermore, operation and reliability are significantly improved. And, a lens operation self-test system, using the lens' built-in microcomputer, can even warn of malfunctions through the camera's LCD readout to help ensure high reliability.

Specifications

Focal Length: 17-55mm
35mm Equivalent: 27-88mm with EOS 30D, EOS 20D, EOS Digital Rebel XT, EOS Digital Rebel
Maximum Aperture: 1:2.8
Minimum Aperture: 22
Lens Construction: 19 elements in 12 groups
Diagonal Angle of Viewn: 78º30' - 27º50'
Focus Adjustment: AF with full-time manual
Focus Drive: Ultrasonic
Closest Focusing Distance: 0.35m / 1.15 ft.
Zoom System: 5-group helical zoom (front group moves: 27mm)
Filter Size: 77mm
Max. Diameter x Length: 3.3" x 4.4" / 83.5 x 110.6mm
Weight: 22.8 oz. / 645g

Canon EF Lenses
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