$969.99 As Advertised
While it is an excellent lens when used with an analogue SLR camera, the EF17-40mm f/4L USM is especially well suited for digital SLR cameras with an imaging sensor size smaller than the 35mm format. Indeed on such digital SLR cameras these focal lengths can give an angle of view approximately equivalent to that of a 28-70mm lens used on a 35mm camera, which makes it the ideal standard zoom lens.
The EF17-40mm f/4L USM has 12 lens elements arranged in 9 groups. Super Spectra Coating on the elements ensures excellent color balance and minimizes ghosting and flare. To provide superb image quality over a 17-40mm zoom range the lens uses three aspheric elements of two different types, while Super UD (Ultra-low Dispersion) glass is used to prevent the chromatic aberrations that often can degrade the subject edge clarity.
Minimum focusing distance is just 28mm throughout the entire zoom range. The Auto-focus works silently and quickly thanks to a fast central processing unit with an improved AF algorithm. You can override AF mode with manual focus should you wish. Controlled by an electromagnetic diaphragm, the EF17-40mm f/4L USM's circular aperture can achieve a more attractive appearance to out of focus background areas in a picture. The front of the lens does not rotate as you focus. This means, for example, that polarizing filters still function effectively as you zoom in and out. At the rear of the lens there's a drop-in gelatin filter holder. Highly resistant to moisture and dust, the EF17-40mm f/4L USM is ideally suited for use in harsh environments. Environment friendly lead-free glass is used throughout its construction.
Canon EF - Zoom lens - 17 mm - 40 mm - f/4.0 L USM - wide angle - Canon EF
Canon EF zoom lens - wide angle - 17 mm - 40 mm is rated out of 5 by 56.
Rated 5 out of 5 by jazzman from Great value for the buck! Was looking for a used 16-35 mm zoom for shooting landscapes and came across this lens. It may not be as fast but it is as sharp and just as reliable. Depending on your needs, this is an excellent lens either as your go-to lens or as a back-up.
Date published: 2016-09-27
Rated 5 out of 5 by Agachado from Razor sharp shots, fast auto focus This is an outstanding workhorse lens. Images come out crystal clear, and the build is everything you expect from an "L" series lens. I couldn't be happier with it.
Date published: 2016-03-05
Rated 5 out of 5 by 1961SG from Excellent value in a wide angle zoom This lens is a "L" series lens, that is it belongs to Canon's series of professional lenses. Because of this the build quality is very high. Not many plastic parts here and it has a dust shield on he mount. Un-like other Canon consumer lenses all "L' series lenses come with the $60 lens hood included. This is a full frame lens which means it has a bigger circle of confusion #the circle of light that exposes the sensor# so when used with a camera that has an APS-C sensor #Rebel series, D-10, 20, 30, 40, 50, 60, 70, D-7 & D-7 II# there is a magnification of 1.6 times turning this lens into a 27-64mm, but because the circle of confusion is larger the quality in the center which the APS-C camera uses is even higher that that of most professional lenses. All this for not much more than the consumer quality 18-135mm. When looking for the professional "L" series lenses look for the red band around the front of the lens or the white coloured telephoto lenses. You won't be disappointed
Date published: 2015-12-14