The Canon EW-83E Lens Hood is primarily designed to prevent unwanted stray light from entering the lens by extending ... shading In addition, since the end of the lens is extended, you also get the added benefit ... extra protection from accidental impact.Dedicated lens hoods, such as the Canon EW-83E, are designed to match ... the specific focal length of the lens it was designed for.Canon EF-S 10-22mm F3.5 ...