Gary Wolstenholme takes a look at this popular lightweight ultra-wide angle zoom lens, which has a constant aperture of f/4, an Ultrasonic focusing motor and sealing against the elements.

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

I was surprised to get an "L" lens at this price. This one definitely deserves the "L" in build and optics. It'd been my go-to lens since I bought it in March. Each lens has its odn personality, and I really like this one. My clients like it too.

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

Heavy

I was surprised to get an "L" lens at this price. This one definitely deserves the "L" in build and optics. It'd been my go-to lens since I bought it in March. Each lens has its odn personality, and I really like this one. My clients like it too.

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

Heavy

I was surprised to get an "L" lens at this price. This one definitely deserves the "L" in build and optics. It'd been my go-to lens since I bought it in March. Each lens has its odn personality, and I really like this one. My clients like it too.

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

Heavy

I have been a Canon enthusiast for years using most of their powershots S, SD, G series.

Compact for L lens; sharp; good colors; good built

no IS; not good for indoors/poor lighting

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.

In the early days of digital SLRs, before the arrival of its smaller-format EF-S lenses, the 17-40mm was one of the mainstays of the Canon range, a super-wideangle zoom for the full-frame EOS 1Ds but also the nearest thing at the time to a ‘standard' zoom for the newer, smaller-format EOS models

Covering both full-frame and APS-C sensors, the EF 17-40mm has proved popular with photographers since its launch – and for good reason

Build quality; promises only what it can deliver in style

Limited focal range; no IS

I use to have the Tamron 17-50 f/2.8. I sacrificed the f2.8 max aperture for Canon L glass and build quality. I'm glad I did. My past Tamron accumulated much dust over its use and non-Canon lenses have poor resale value.

Weather-resistant construction; Affordable L series lens; Light weight

The lens hood blocks the built in flash in my former Canon 30D

this is one of canons top of the range lenses, you cant get any better than this just look for the red ring on the lens barrel and you can tell its a top of the range lens ive had one now for about 2 years and its a permanent fixture on my camera i use it as a Walk-About-Lens works on both full

Awesome Picture Quality; Build Quality; Canon; Fits APS-C; Fits Full Frame; Sharp; TOP OF THE RANGE