articles | galleries | reviews | forum | users | exhibitions Login | Register

Author: ea
Viewed: 2025 times
Modified: Aug 26, 2006

9.0 (from 1 votes)

Add to   Add to
Add to   Digg this page!

Articles > Lens news Aug 25, 2006  11:19
Canon's new lens: EF 70-200mm F4L IS USM

Image stabilized version of the current EF 70-200 mm F4L. With this new stabilized lens Canon are boasting no less than 4 stops of stabilization (meaning you could use a shutter speed 4 stops/EVs slower than without it). Despite the addition of image stabilization the lens remains the same size as its non-stabilized sibling and is only slightly heavier. This lens should be available in November for $1250 (US).

The EF 70-200mm f/4L IS USM features

  • Compact lightweight body - 760g, 172mm length
  • 4 stop Image Stabilizer with 2 modes
  • 1 x Fluorite and 2 x UD lens elements for superior optical performance
  • Ring type USM auto focus with full time manual override
  • Circular aperture diaphragm for even background blur
  • Environmental seals for dust and moisture resistance
  • Super Spectra coatings to suppress ghosting and flare
  • 1.2m minimum focus distance
  • Lens hood and soft pouch

The EF 70-200mm f/4L IS USM offers a lightweight alternative to the renowned
EF 70-200mm f/2.8L IS USM, complementing Canonís other professional L-series lightweight zooms such as the EF 17-40 f/4L USM and EF 24-105L IS USM. f/4L lenses are designed for professional photographers requiring a light zoom lens with a fixed aperture throughout the zoom range. The lens adds Canonís proven Image Stabilizer technology to the popular EF 70-200mm f/4L USM while maintaining that lensí compact size.

Image Stabilizer
4 step Image Stabilizer (IS) extends low light options to previously unimaginable levels. Photographers normally shooting handheld at 1/250 sec can switch on IS to obtain a similarly steady and blur-free result with a shutter speed of just 1/15 second.

IS reduces dramatically the image blur caused by camera shake. Gyro sensors detect unwanted vibrations, triggering the corresponding movement of a correcting lens group perpendicular to the optical axis. This alters the light path, returning the image to its correct position on the sensor or film plane.

For shooting immobile subjects, Mode 1 corrects for movement in the image along both the horizontal and vertical axes. For shooting while panning horizontally to follow a moving subject, Mode 2 turns off vertical correction and prevents the effect of dragging the subject back through the frame.

IS switches off automatically when the camera is mounted on a tripod, thus preventing feedback loops between the IS sensor and internal motor vibrations.

Superb auto-focus
The lensí Ring-type USM employs ultra-sonic frequency vibrations to drive auto focus with unrivalled speed and near-silent operation. A powerful CPU and improved AF algorithm contribute to speed performance. Good holding torque stops the lens with precision and accuracy, the instant it arrives at the correct focus point and without overshoot. Photographers can switch to manual focus instantly and at any time simply by moving the manual focus ring without first having to switch out of auto focus mode.

f/4 from 70 to 200mm
The EF 70-200mm f/4L IS USM offers the highest possible optical quality with no change in aperture over the full focal range of the lens. This allows photographers to set exposure at the widest aperture and zoom all the way through to 200mm without having to decrease shutter speed. Lens length does not alter during zooming and the front lens element does not rotate during zooming or focusing. The lens employs an almost perfectly circular barrel aperture, helping create attractive, even background blur.

Image quality
A newly designed optical system limits lens size and improves image clarity over the total image area. 1 x Fluorite element and 2 x Ultra-Low Dispersion glass elements are used to eliminate the secondary chromatic aberrations that otherwise reduce sharpness and introduce colour fringing. By optimising Super Spectra lens coatings and lens element shaping, Canonís engineers have been effective in suppressing flare and ghosting Ė more prone to occur with digital cameras due to reflection off the image sensor. By increasing light absorption, coatings reduce reflections off lens element surfaces to deliver crisp, undistorted images with natural colour balance.

EOS system integration
The EF 70-200mm f/4L IS USM includes distance metering information, providing compatibility with the E-TTL II flash system of late model cameras such as the EOS-1D Mark II, EOS-1Ds Mark II, EOS 5D and EOS 400D. When used in conjunction with Canonís range of EX Speedlite flash units, the lens passes distance information to the flash algorithm for markedly improved flash exposure metering. To match the weather resistance afforded by EOS-1 pro camera bodies, an O-ring seals the lens against the lens mount to prevent the ingress of dust and moisture.

AF Mode and IS switches have been reshaped, making them less susceptible to being engaged or disengaged accidentally.

The EF 70-200mm f/4L IS USM comes with a lens hood and lens pouch.

In keeping with Canonís Kyosei philosophy of living in harmony with the environment, the lens features only lead-free glass.
Page 1 (of 1)

Similar articles

Article discussion >>>

© 2005 all rights reserved. | about | help