The dedicated Vello ES-62 Lens Hood with Adapter is specifically designed for use with the Canon EF 50mm f/1.8 II Lens.
Lens hoods are primarily designed to prevent flare associated with unwanted stray light by shading the front of the lens barrel. A dedicated lens hood is designed to perfectly match the focal length and design specifications of a given lens. In addition, hoods provide extra protection from accidental impact.