Conclusion

The Canon EF 16-35mm f/4L IS USM is a very capable but also very pricey ultra-wide-angle zoom lens that will appeal most to landscape, architecture and reportage photographers looking for a lightweight and responsive lens with the added advantage of image stabilisation for low-light hand-held work.

Given its L-series billing, the Canon EF 16-35mm f/4L IS USM build quality is reassuringly excellent and it makes a perfect partner to a full-frame Canon DSLR like the EOS 5D Mark III that we tested it with. Auto-focusing is quiet and quick, with the ability to manually override it and focus manually if required proving a nice touch. The capable image stabilisation system used in conjunction with a high-ISO monster like the 5D Mark III is a low-light shooter's dream ticket, making it easy to hand-hold the camera and get the shot, despite the relatively slow maximum aperture of f/4.

Image quality is generally excellent. Chromatic aberrations are very well controlled, bokeh is quite impressive despite the f/4 aperture and the wide-angle nature of the lens, and the Super Spectra coatings successfully prevent contrast loss attributable to flare. The only real optical issues are some vignetting throughout the zoom range and, obvious barrel distortion at the 16mm wide-angle focal length, and a slight lack of sharpness when shooting wide-open at f/4 at the 16mm and 35mm settings.

If you can afford the hefty price-tag then we can highly recommend the Canon EF 16-35mm f/4L IS USM as an excellent wide-angle zoom lens for Canon full-frame DSLR owners.

Ratings (out of 5)
Design	4.5
Features	4.5
Ease-of-use	4.5
Image quality	4.5
Value for money	4