The Canon EF 17-40mm f/4L USM Ultra Wide Angle Zoom Lens is a very high quality lens that is sold for a competitive price, making it one of Canon’s best-selling “L” series lenses. When used on a full frame DSLR camera, the 17-40 f/4L acts as an ultra wide-angle lens, which makes it ideal for… Continue reading Canon EF 17-40mm f/4L USM Ultra Wide Angle Zoom Lens