The Canon ES-79II is the most important
accessories for each lens you own.
A lens hood provides multiple functions:
1-It shades the lens from stray light, improving your contrast and image
2-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
For more information about, Canon ES-79II Hood for EF 85mm & F1.2L 80-200mm f2.8L Lenses .