Lens hoods are primarily designed to prevent unwanted stray light from entering the lens, extending and shading the edge of the lens. Additionally, as the lens hood is extended, it also provides extra protection from accidental impact.

The "petal" shape of this lens hood maximizes the coverage of the hood with the minimum possible weight and area. This specialized lens hood is designed to fit the specific focal length of the lens for which it was made.

• Canon EW-78II lens hood for EF 35-350mm f/3.5-5.6L lens