Canon EF Lenses

Canon EF-S 17-85mm f/4-5.6 IS USM Zoom Lens

Particularly among advanced amateur and professional photographers, there has been a growing need for affordable zoom lenses that support true wide-angle and ultra-wide-angle photography. By reducing the distance from the rear of the lens to the focal plane and reducing the size of the image circle to match the size of the APS-C imaging sensor used in digital SLRs such as the EOS 20D camera and Digital Rebel camera, Canon's EF-S lenses reduce the size, weight and cost of wide-angle lenses for these cameras while at the same time producing high image quality with superb resolution and contrast at all focal lengths.

This new EF-S lens brings true wide-angle to telephoto coverage to EOS 20D camera and Digital Rebel camera photographers. It features Canon's Image Stabilization system, allowing safe hand-held photography at shutter speeds up to three steps slower than otherwise possible. And of course, it's optically optimized for digital SLRs. A ring-type USM delivers fast and silent auto focus, as well as full-time manual focus when in the AF mode.

The EF-S 17-85mm f/4-5.6 IS USM lens provides a 5x zoom ratio and an angle of view equivalent to a 27-136mm lens on a 35mm camera. The new lens also uses a glass-molded aspherical lens element with aspherical surfaces on both sides for superb image quality throughout the entire zoom range and it features a closest focusing distance of 12 inches at all focal lengths. The EF-S 17-85mm IS lens is 5% shorter and 12% lighter than the EF 28-135mm IS lens and accepts 67mm filters.

Canon EF-S 17-85mm f/4-5.6 IS USM

Features and Specs | Large Image

Key Features of the Canon EF-S 17-85mm f/4-5.6 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.
17-85mm Zoom Range: Compact and lightweight ultra-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. 17-85mm (equivalent to a focal length of 27-136mm in 35mm format), 5x zoom ratio.
Ultrasonic Motor: Powered by Canon's exclusive Ultrasonic (USM) motor for autofocusing, the EF-S 17-85mm f/4-5.6 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.
Minimum Focusing Distance of 0.35m at all Focal Lengths
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: 17-85mm
Maximum Aperture: 1:4-5.6
Minimum Aperture: 22 ~ 32
Lens Construction: 17 elements in 12 groups
Diagonal Angle of Viewn: 78º30' - 18º25'
Focus Adjustment: Inner focusing system with focusing cam
Closest Focusing Distance: 0.35m / 1.15 ft.
Zoom System: Ring USM
Filter Size: 67mm
Max. Diameter x Length: 3.1" x 3.6" / 78.5 x 92mm
Weight: 16.8 oz. / 475g

Canon EF Lenses
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