What is the main purpose of a lens hood?

A lens hood serves a crucial function in photography by reducing lens flare and protecting the lens. When strong light sources hit the front element of a lens at certain angles, it can create unwanted reflections and reduce image contrast, which results in lens flare. A properly designed lens hood extends out from the lens, blocking light that may enter from the sides, thereby minimizing the potential for flare and enhancing the overall image quality.

In addition to its flare-reducing abilities, a lens hood also provides a physical barrier against accidental contact, helping to protect the lens from scratches, dust, and moisture. This aspect is particularly important in outdoor photography where environmental factors can easily compromise lens integrity.

While enhancing color saturation or improving depth of field are important aspects of photography, they are achieved through different techniques, such as adjusting camera settings or using specific filters. Increasing the camera's ISO pertains to adjusting the sensitivity to light, which does not involve a lens hood. This makes the primary function of a lens hood specifically focused on reducing flare and providing lens protection.