The Canon EF 17-40mm may deliver spectacular ultra-wide angle coverage when fitted to a full-frame body like the EOS 5D, but offers a more normal, general-purpose range when mounted on cropped bodies like the EOS 30D or 400D / XTi.

Canon 'L' build and optical quality; Fast and quiet USM focusing motor; Constant f4 aperture throughout range; Will also work on full-frame body

Shorter zoom range than kit lens; No IS (although not particularly necessary; Overkill if not considering full-frame in future; Canon EF-S 17-85mm more flexible for most

Gary Wolstenholme takes a look at this popular lightweight ultra-wide angle zoom lens.

Superb performance in the centre throughout the range; Well built; Lightweight

Sudden softness in the corners may disturb full-frame SLR users; Distortion difficult to correct entirely at 17mm; Falloff at 17mm

It's not exactly easy to design a flawless full format lens and the Canon EF 17-40mm f/4 USM L shows its part of the struggles here. The lens is not overly fast but it has a comparatively broad range for a lens in this class and it seems as if Canon has overstretched things a little with respect to...

The Canon EF 17-40mm f/4L USM ($839.99 direct) is an ultra-wide to normal zoom lens that is compatible with Canon EOS SLR cameras. When used on a full-frame body, the lens provides an extremely wide 17mm field of view on the wide end with a 2.4x zoom factor that takes it to a normal 40mm field of...

The Canon EF 17-40mm f/4L USM lens is an inexpensive alternative to the 16-35mm f/2.8, but its edges are muddy at its widest angle. (3 out of 5) Pros Ultra-wide field of view Reasonable price tag Good center sharpness Cons Muddy edges and corners at 17mm Some distortion Noticeable color fringing The...

Ultra-wide field of view; Reasonable price tag; Good center sharpness

Muddy edges and corners at 17mm; Some distortion; Noticeable color fringing

A lovely lens for the price, very fast to focus and very quiet. I use it on a 600D body so only use the centre area of the lens. I suffer no curving on the edges as full frame sensors are reputed to suffer. As you would expect for a "L" series lens, it's built like a tank with weather sealing.

Consistent Output; Easily Interchangeable; Quick Focus; Rugged; Sharp Focus; Strong Construction

I have recently used this lens for landscape and seascape images in mostly good outdoor light on two full-frame cameras, namely the EOS 5D and EOS 5D Mark III respectively. Although it covers a range of focal lengths I already had mostly covered by three prime lenses, I did not previously possess...

Robust and impressive build quality with smooth handling; relatively lightweight; reliable autofocus; familiar vibrant Canon colours; Well priced (at least by 'L' standards)

Very weak corner resolution at 17mm below f/11 on full-frame; The bulbous and ugly lens hood is large, obtrusive and awkward to pack unattached

Canon makes two high-quality wide-angle zoom lenses for full-frame cameras, the 17-40/4L reviewed here and the Canon EF 16-35mm f/2.8L II USM , ( compare prices ). In the digital era, the 17-40 has been overlooked to some extent.

Canon EF 17-40mm f/4L USM is one of Canon's professional grade lenses, first released in May of 2003. It is one of only four ultra wide zoom lenses Canon manufactures at this time.

Because it is a very high quality but moderately-priced ultra wide angle zoom lens, the Canon EF 17-40mm f/4L USM Lens is one of Canon's best selling lenses. The 17-40 f/4L fills out the bottom focal length range of Canon's f/4L zoom lens series .