LENS HOOD FUNCTION: Used to block the sun or other light source in order to prevent glare and lens flare. A universal screw-in type lens hood for all brands lenses, comes with rotating ring. WHEN TO USE A LENS HOOD: Lens hoods are used to keep stray light out of your lens. Stray light can cause lens flare and occasionally, can do harm to your camera or your film. Lens hoods are ideal for when it is extremely sunny outside; this is really the only time you will ever “need” a lens hood. Nightlife photographers often use lens hoods to keep out stray stage and club lights. Some enthusiasts prefer to use lens hoods all the time because stray light can occur in unlikely places ADVANTAGE OF ATT LS SERIES LENS HOOD: Screw-in (Screw Mount) lens hood High quality smooth outside and mate inside finish Adopts brand-new design (patent pending) Divides into two parts, easy to reverse attach into lens body Save space to put it into camera carrying bag etc Can use along with snap-on lens cap Suitable for digital video cameras of all brands