Canon’s EF 16-35mm f4L IS USM is an ultra-wide zoom that’s compatible with full-frame DSLRs. It’s the successor to the EF 17-40mm f4L USM, losing a little on the long-end, but gaining a tad on the important wide-end, while also adding the benefit of image stabilization. Crucially it matches the coverage of the EF 16-35mm f2.8 USM models, at a comfortably lower price which will make it a popular choice for those with lower-cost full-frame bodies or those who don’t need an f2.8 aperture. But don’t let the lower price fool you: as a modern optical design, it performs very well even with the highest resolution bodies.