Canon

EF 16-35/2.8 LU

Key Features of the Canon EF 16-35mm f/2.8L USM Zoom Lens

Ultrasonic Motor

Powered by Canon's exclusive Ultrasonic (USM) motor for autofocusing, the EF 16-35mm f-2.8L USM is silent in operation and very quick to focus, even in low-light conditions. 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.

Ultra-Low Dispersion UD Glass

Lenses made from fluorite are extremely expensive due to the high cost of synthetic fluorite crystal production. UD (ultra low dispersion) glass made an appearance in the latter half of the 1970's, delivering a special optical glass which could provide characteristics similar to fluorite but at a lower cost and thereby answering another desire of lens designers. While the index of refraction and dispersion of UD glass are not as low as fluorite, they are significantly lower than other types of optical glass. Moreover, UD glass does display similar partial dispersion characteristics. The selection of the proper lens element combination in consideration of the intended focal length and other factors can provide close to the same effect as fluorite, (two UD lens elements are equivalent to one fluorite element). Super UD glass was introduced in 1993 as a new material that achieves almost the same performance as fluorite while achieving a new balance of cost reduction and higher quality.

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.

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.

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.

Inner/Rear Focusing

Focusing is performed by moving one or more lens groups positioned between the front lens group and the diaphragm.

Dust- and Water-Resistant Construction

This EF lens is highly dust- and water-resistant and can therefore be used in harsh conditions without dust and water getting inside.

Specifications

Focal Length

16-35mm

Maximum Aperture

1:2.8

Lens Construction

14 elements in 10 groups

Diagonal Angle of View

108� 10' - 63�

Focus Adjustment

Inner Focusing System with USM

Closest Focusing Distance

0.9 ft./ 0.28m

Zoom System

Rotating type

Filter Size

77mm

Max. Diameter x Length

3.3" x 4.1" / 83.5 x 103mm

Weight

1.3 lbs. / 600g