This affordable L-series ultra-wide-angle zoom lens that's ideal for both film and digital SLRs. Superior optics are assured by the use of three aspherical lens elements, in addition to a Super UD (Ultra-low Dispersion) glass element. Optical coatings are optimized for use with digital cameras. This lens focuses as close as 11 inches (0.28m), and offers both Canon's full-time manual focus and a powerful ring-type USM for fast and silent AF. It has a constant f/4 maximum aperture, and offers the choice of screw-in 77mm filters or a holder in the rear of the lens for up to three gel filters. Finally, it offers weather-resistant construction similar to other high-end L-series lenses.Three Aspheric Lenses1 Super Ultra-low Dispersion glass element Inner/Real FocusingFull-Time Manual FocusingCircular ApertureEF 17-40mm f/4.0L USM Zoom LensLens Case LP1319 Lens Hood EW-83E
Average Customer Rating:
Rating Breakdown1 review
1 out of 1(100%)reviewers would recommend this product.
Customer Reviews for Canon EF 17-40mm f/4.0L USM Zoom Lens
Review 1 for Canon EF 17-40mm f/4.0L USM Zoom Lens
Great wide angle lense
PostedApril 14, 2011
from Anaheim, CA
This is an extremely sharp lense. Thru live view mode, this lense produces images that are in focus. Too bad it's not a faster lense, due to the difficulty trying to focus on the subject in low light situations. Other than that, great lense!