Camera Lens Parts: Lens Hood
A lens hood is a necessity to every photographer on a bright, sunny day. There are two major reasons for the use of a lens hood, and these make them worth the extra bit of expense and inconvenience.
Preventing Glare and Flare
The main purpose of the lens hood is to prevent glare on the lens and to keep lens flare from appearing in images. This is accomplished by blocking the light source from the sides and keeping it from hitting directly on the main glass of the lens. Photos taken with a lens hood should have more vivid and saturated color tones, while those taken without the hood may appear hazy or have numerous lens flare rings.
Lens hoods are excellent for protecting the lens from accidental touches, fingerprints and scratches. Also, some impact protection can be gained since it helps to give the lens something to cushion or break the fall if dropped. Longer lens hoods for zoom lenses can even offer some protection from the outdoor elements like dust and rain, but this is not feasible with wide angle lenses due to their very short length.