EF-S 17-85mm f4-5.6 IS USM
Ideal for travel, mid-range wildlife and general photography, the EF-S 17-85mm f4-5.6 IS USM is a high quality, lightweight all-purpose 'standard' zoom lens. This 5x zoom lens offers the widest range of any lens in this class and features Canon's latest optical Image Stabilizer technology, providing up to 3-stops compensation for image blur caused by camera shake and slow shutter speeds.
Image stabilization uses two motion-sensitive gyros within the lens. These pass information to a floating element which moves at right angles to the lens axis to keep image stationary on the film or sensor. The system can cope with hand-held movement or vehicle vibrations.
The lens includes one double-sided aspherical element for crisp,high contrast, corner-to-corner detail.
The lens features Canon's EF-S lens mount, matched to the EOS 20D and EOS 300D digital SLRs. The APS-C sensor of these cameras is smaller than a 35mm film frame. This changes the field-of-view between the two formats. The EF-S 17-85mm kens gives a simliar view to a 28-135mm lens on a 35mm camera.
The EOS 20D and EOS 300D are compatible with all EF lenses, while EF-S lenses only fit these two cameras. The 'S' in EF-S stands for 'short back focus'. This describes the system that allows the rear lens element of EF-S lenses to be positioned closer than normal to the image sensor of APS-C sensor cameras. A white lens mount index differentiates the EF-S lenses from EF lenses, which retain their traditiional red marking. A rear rubber ring prevents any damage in the event that an inadvertent attempt is made to mount the lenses on non-compatible cameras.
The ring-type USM motors found in btoh lenses employ ultrasonic frequency vibrations to drive focusing with unrivalled speed. Canon's ring-type USM holds the lens with precision and accuracy the instant it arrives at the correct focus point and without overshoot. To further improve accuracy and speed, the drive patterns of both new lenses are tailored to specifically match the EOS 20D and EOS 300D. Both lenses also feature full-time manual focus overide.
The lens incorporates an EMD (electromagnetic diaphragm), which employs an almost perfectly circular barrel aperture. This helps create an attractive, even background blur when the photographer minimises depth-of-field to isolate a subject.
Perfect for digital
By optimising lens caotings, Canon's engineers have been effective in suppressing flare and ghosting, which are more prone to occur with digital cameras due to reflection off the image sensor. Coatings reduce reflections off the lens surfaces to deliver crisp, undistorted digital images with natural colour balance.
Both lenses include new distance metering information, providing compatibility with the E-TTL II flash system of the EOS 1D Mark II, 20D, 30V Date, 33V and 300X. When used in conjunction with EX Speedlite flash units, this provides improved flash exposure metering.
An optional lens hood accessory is available for both lenses. In keeping with Canon's stringent environmental policy, only lead-free glass is used in the lens' optics.
Diagonal angle of view: 78°30' to 18°25'
AF drive system: Ring USM
Manual focusing: Enabled with focus mode switch and focusing ring (full time manual focusing)
Focusing range: 0.35m to infinity
Maximum magnification: 0.07x(wide); 0.2x(tele)
Minimum aperture: f32
Aperture blades: 6
Filter diameter: 67mm
Diameter x length: 78.5 x 92mm
Lens hood/lens cap: EW-73B/E-67U
Lens case: LP1116
Lens extender EF: not compatible