Product Description

The EF17-40mm f/4L USM is an ultra wide angle Canon EF zoom lens meant for professional and high amateur SLR EOS camera users.While it is an excellent lens when used with an analog 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.

Product Details

• Brand: Canon
• Model: 8806A002
• Dimensions: 5.20" h x 5.40" w x 7.20" l, 1.10 pounds

Features

• 17-40mm ultra-wide-angle zoom lens with f/4 maximum aperture for Canon SLR cameras
• 3 aspherical lens elements and super UD glass element create superior optics in all conditions
• Powerful ring-type ultra-sonic monitor (USM) produces fast and silent autofocusing
• Focuses as close as 11 inches; supports screw-in 77mm filters or up to 3 gel filters
• Weather-resistant construction; measures 3.3 inches in diameter; 1-year warranty

Amazon.com Product Description
Broaden your perspective with the Canon EF 17-40mm ultra-wide-angle zoom lens. Ideal for both film and digital SLR cameras, the lens offers three aspherical lens elements in addition to a Super UD (ultra-low dispersion) glass element, creating superior optics in all conditions. In addition, the lens focuses as close as 11 inches (0.28mm), and offers both Canon's full-time manual focus and a powerful ring-type ultra-sonic monitor (USM) that produces fast and silent autofocus. Other features include a constant f/4 maximum aperture, the choice of screw-in 77mm filters or a holder in the rear of the lens for up to three gel filters, and optical coatings optimized for use with digital cameras. Boasting weather-resistant construction similar to other high-end L-series cameras, the lens carries a one-year warranty.

• Focal length: 17-40mm
• Maximum aperture: 1:4
• Lens construction: 12 elements in 9 groups
• Diagonal angle of view: 104 to 57 degrees (at 30 feet)
• Focus adjustment: Inner focusing system with USM
• Closest focusing distance: 0.9 feet
• Zoom system: Rotating type
• Filter size: 77mm
• Dimensions: 3.3 inches in diameter, 3.8 inches long
• Weight: 1.1 pounds

From the Manufacturer
A new and affordable L-series ultra-wide-angle zoom lens that's ideal for both film and digital SLRs. Superior optics are assured by the use of three Aspherical lens elements, in addition to a Super UD (Ultra-low Dispersion) glass element. Optical coatings are optimized for use with digital cameras. This lens focuses as close as 11 inches (0.28m), and offers both Canon's full-time manual focus and a powerful ring-type USM for fast and silent AF. It has a constant f/4 maximum aperture, and offers the choice of screw-in 77mm filters or a holder in the rear of the lens for up to three gel filters. Finally, it offers weather-resistant construction similar to other high-end L-series lenses.

About half the price of the 16-35 f/2.8 lens, this L-series lens has an entirely new optical design with three Aspherical elements and a Super UD-glass element. The combination provides superb contrast and sharpness, even at the widest settings. It’s ideal for both film and digital SLRs, and features the same weather-resistant design, rear gel filter holder, and high-speed Ultrasonic Motor as the EF 16-35mm lens.

Customer Reviews

Great wide angle range.
I got this lens for my full-frame camera (5D), and it's a great lens to get into wide angle photography - sharp and versatile, plus it's very nicely priced for an L lens. Be aware that the crop factor of APS sensor cameras makes this lens more of a 27-64mm. If you have one of these cameras and you really want to have ultra wide-angle capability, you might be better off with something like Canon's EF-S 10-22mm.

makes you better
photography is my hobby. i do enjoy it and wanted to improve. i bought this lens to give more range to my lens. i have, the kit lens for my 30D and a 70-200 f2.8L. the telephoto was just too heavy for everyday/walk around use. the 17-40 fits the bill. i have shot about 2000 pictures. i would say about 20% are keepers (because i am learning). focusing at such a wide perspective (i got the hang of it about 250-500 shots) does take some getting used to. the lens does teach you a lot about f stops, lighting, and composition when in full manual. overall, the quality of the lens is outstanding. sunsets and "vista in the southwest" are when i appreciate this lens. i was most surprised at how good it works in close quarters. for example, my kids walking around the mall. it is expensive, but the EF 16-35 f2.8L, was simply out of my range. it is better than the kit lens for sure. i would agree with the majority of the positive reviews. the only drawback is the price, but i feel it is well worth it. AMAZON did not get the product to me as quickly as promised, but they did wave the shipping when i pointed it out.
in summary, if you are wanting to improve your skills in photography, then this lens is a great addition. it will not take better pictures, it will make you a more refined photographer/artist. as with all things worthwhile, it will cost you something.

Great lens for many different types of shots
This lens offers a fast lens with just the right amount of wide-angle. I've been using it for landscaping shots, up close, action, low light and its really impressed me. I would recommend this lens to anyone who wants to take their photography to the next level.