Canon EF 17-40mm f/4L USM Ultra Wide Angle Zoom Lens for Canon SLR Cameras from Digital Camera Showroom

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.

Canon EF 17-40mm f/4L USM Ultra Wide ...- User Rating:
Summary for Canon EF 17-40mm f/4L USM Ultra Wide ...- Great Lens
Notes on Canon EF 17-40mm f/4L USM Ultra Wide ...- I bought this with my Canon 30D. This is a great lens and L series is the best. I have mostly L lens because the quality is worth the money.

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Canon EF 17-40mm f/4L USM Ultra Wide ...- User Rating:
Summary for Canon EF 17-40mm f/4L USM Ultra Wide ...- Great on full frame, average on crop bodies
Notes on Canon EF 17-40mm f/4L USM Ultra Wide ...- This is a good lens, but it's certainly not great. Along with all other L-series lenses, it's more durable, weather resistant, doesn't rotate the front element. It has a virtually silent focusing motor which is a pleasure to use. The lens is light, feels solid.

But as far as quality is concerned, it's average. On a full-frame camera, such as the 1Ds or the 5D, the corners are much sharper than that of a 28-135, for example. But on a cropped-sensor camera such as the 40D or the XTi, you will not see almost any difference in quality between this and the 18-55mm kit lens. I've tried, you just can't. If you're trying to stay on a budget, look into the cheaper EF-S, Sigma or Tokina alternatives.

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Canon EF 17-40mm f/4L USM Ultra Wide ...- User Rating:
Summary for Canon EF 17-40mm f/4L USM Ultra Wide ...- newest most used glass!
Notes on Canon EF 17-40mm f/4L USM Ultra Wide ...- this lightweight little wonder is always on my camera, i really hardly ever take it off...i do however, find the hood a bit...much, that being said the feel and operation is obviously that of an 'L' lense

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Canon EF 17-40mm f/4L USM Ultra Wide ...- User Rating:
Summary for Canon EF 17-40mm f/4L USM Ultra Wide ...- AMAZING
Notes on Canon EF 17-40mm f/4L USM Ultra Wide ...- I bought this product for my sons graduation. He absolutely loves it!! He had wanted it for a long time and he said it was worth waiting for. Thanks for the great service also.

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Canon EF 17-40mm f/4L USM Ultra Wide ...- User Rating:
Summary for Canon EF 17-40mm f/4L USM Ultra Wide ...- I'm happy.
Notes on Canon EF 17-40mm f/4L USM Ultra Wide ...- I debated for quite a while between this lens and the 17-55 f/2.8 EF-S IS. I'm still drooling over that lens, but what it came down to in the end was my plan to upgrade to the 5D when, and if the Mark II is released. Of course, the other lens that could have made the decision even more difficult is the 16-35 f/2.8L, but it was way out of my price range.

I'm happy with my choice. The lens is well built and sharp. If I have any complaints it would be CA. This lens does tend to show a bit of color fringing, but nothing and extra five seconds in raw processing can't fix. So I guess that point is moot.

Overall, this is a good lens. Well worth the money. Especially at this price.

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