Canon
The Canon EW-78BII is a dedicated bayonet-mount lens hood, this one being made by Fotodiox. It is designed to fit lenses like the Canon EF 28-135 mm f/3.5-5.6 IS (and other compatible lenses). A lens hood is a simple optical accessory that extends the front of the lens and blocks stray light from hitting the front element at oblique angles, which helps reduce lens flare and ghosting in images by limiting unwanted light that can wash out contrast or create haze. It also provides extra physical protection for the lens against bumps, light impact, dust, and the elements. EW-78BII hoods are typically made of lightweight, matte-black plastic with a non-glare interior surface to maximize shading and minimize internal reflections. The bayonet mount lets the hood twist securely onto the lens, and many can be mounted in reverse for more compact storage when not in use.
