Canon EF 17 40mm F4 L Lens

An 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 28cm, 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