Photographing without a lens hood attached to the front of the lens is like playing first base without a glove. Similarly, we can’t imagine a baseball catcher trying to stop fast ball pitches without his specialized mitt and its deep central pocket to stop them.
The camera is actually a catcher’s mitt for light rays and very similar to the human eye. Bright light shining across or directly into our eyes is uncomfortable and causing us to squint or seek some means of blocking it. This is why motor vehicles are equipped with sun visors that enable us to see more clearly and safely on the highway. This is also why most camera lenses include a lens hood.
That lens hood is a sun visor that blocks glare on the lens surface and excludes peripheral light that can trigger incorrect light meter readings that may underexpose photos or produce images that appear milky or foggy.
For the best photographic images possible, we seek to capture light reflected directly from our subject while excluding as much extraneous light as possible. This is the key benefit of a lens hood, but the hood also acts as a bumper to physically protect the lens. Use of the lens hood eliminates the need for add-on filters such as UV and Skylight filters that can affect image quality.
Many “point-n-shoot” cameras are not equipped with lens hoods, requiring the user to be especially aware of lens glare and act to shade the lens. This can be accomplished by shooting from a shady location or by physically shading the lens with an object such as one’s hand or hat. Just be certain that the object is out of the field of view.
Consider the lens hood as a funnel for light and a vitally important part of your camera/lens system. ~ Tim Flanigan