Canon EF 17-40mm introduction 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.

This lens, which has become almost legendary amongst Canon users, has been around for a little while now. There are a number of new or updated contenders on the market in what has been a competitive sector. We look at how this war-horse is standing up.

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

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 view at the long end.

Due to popular demand: we look at this much-loved L lens. Here's our video review on this wide-angle zoom with a red ring on it. Pricing Reference: http://www.digitalrev.com/en/canon-ef-17-40-f4-l-usm-zoom-lens-for-dslr-camera