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

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

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

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.

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

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

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

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...