Small and lightweight for its class, the EF 17-40mm f/4L USM combines outstanding L-series build quality with an affordable price tag. Its size makes it easy to carry and comfortable to use, while its versatility and superior optical performance makes it a great general purpose lens. As a landscape lens, the EF 17-40mm f/4L USM features a ring-type ultrasonic motor for superfast, accurate autofocus in near silence, as well as wide open centre and corner sharpness for finely detailed images. Its seven-blade circular aperture delivers excellent OOF (Out of Focus) blur quality, while the lens itself offers superb full frame compatibility and performance. This is a great choice if you are interested in landscape photography or real estate and architecture photography, and is especially handy if you need to work in a tight space!