The EW-72 Lens Hood for EF 35mm f/2.0 IS USM Lens from Canon is a black, petal-style lens hood for the Canon 35mm f/2.0 IS USM Lens. A lens hood is designed to block unwanted stray light from entering the lens and causing flares. It also offers a degree of protection for the lens from accidental impact and the elements. A dedicated lens hood is made to match the specific focal length of its lens, deflecting unwanted light without extending into the image frame.