The Canon EF 17-40mm f/4.0L was announced back in February 2003 as a lightweight ultra wide-angle zoom and has since become a bit of a classic lens for owners of Canon EOS digital and film SLRs.

Its ultra-wide focal range delivers spectacular coverage on film or full-frame digital SLRs, although it’s sufficiently wide to also be considered as a general-purpose zoom on APS-C bodies like the EOS 30D and 400D / XTi. When fitted to an APS-C body, it delivers a range equivalent to 27-64mm, and while the long-end is clearly shorter than general purpose EF-S zooms, it does have the advantage of being compatible with a full-frame body should you wish to upgrade in the future.

In terms of looks and focal range, the EF 17-40mm is closest to Canon’s EF 16-35mm f/2.8L. The EF 16-35mm gets a little wider, although not quite as long, but the big difference is of course focal ratio: the EF 16-35mm with a constant f2.8 aperture is a whole stop brighter than the EF 17-40mm, but that extra stop comes at a high cost. The EF 16-35mm is almost twice the price of the EF 17-40mm, and 100g heavier too. In our view this makes the EF 17-40mm a bit of a bargain, and indeed it’s one of the cheapest ‘L’ lenses available.

In this review we’ve concentrated on using the EF 17-40mm with the full-frame Canon EOS 5D, where its enormous wide angle coverage can be truly unleashed. We’ve compared it against the EF 24-105mm f/4.0L and the older EF 24-70mm f/2.8L, as many photographers will actually consider using the EF 17-40mm as their main general-purpose walk-around lens. While it clearly can’t zoom-in to anything you’d describe as telephoto, the 40mm ‘long’ end makes it more flexible for day to day use than you’d think.

As mentioned earlier though, the focal range also allows the EF 17-40mm to be considered as a premium option for owners of APS-C bodies. We’ve fully tested the EF 17-40mm on an EOS 400D / Rebel XTi and prepared a separate review and video tour dedicated to how the lens performs on a cropped-frame body – see our Canon 17-40mm with EOS 400D review. You can also see how it compares against the more traditional general-purpose EF-S lenses in our Canon EOS 400D lens upgrade group test.

In the meantime, lets take a ride with the EF 17-40mm – one of the most exciting, yet best value options for full-frame bodies like the EOS 5D. Note: the serial numbers of the EF 17-40mm, EF 24-105mm and EF 24-70mm lenses tested were 338244, 305841 and 54788.