Designed to prevent unwanted stray light from entering the lens Ensures no problems with vignetting or motor functions Added benefit of extra protection from accidental impact See product description for list of compatible lenses Lens Hood for EF 85mm f/1.2L & EF 80-200mm f/2.8L USMOne of the most important accessories for each lens you own. A lens hood provides multiple functions: it shades the lens from stray light, improving your contrast and image quality; in inclement weather, it can assist in keeping moisture or wind-blown debris off the lens; and it protects the front barrel from the inevitable impacts against walls, door frames, and other real-life obstacles. Almost all EF and TS-E lenses have a Canon lens hood engineered specifically for it.