The Canon ET-74 Lens hood are primarily designed to prevent unwanted stray light from entering the lens by extending and shading the end of the lens. In addition, since the end of the lens is extended, you also get the added benefit of some extra protection from accidental impact.
Dedicated lens hoods are designed to match the specific focal length of the lens it was designed for. Lens hoods are primarily designed to prevent unwanted stray light from entering the lens by extending and shading the end of the lens.
Acts as a shade (visor) and prevents stray light from entering your lens, thus reducing glare and flare for better visibility and image quality. It also helps to protect your lens, as it adds an extra layer of protection to your front lens element. A must have when your subject is backlit, you’re shooting into or near strong sources of light (like the sun), you’re using off-camera flash that creates lens flare, or when you’re shooting near street lamps, cars with their lights on, buildings etc. Fits to the front of the EF 70-200mm f/4L lens, reducing ‘flare’ caused by light shining directly on the lens’ front element.