UV filters are mainly used to protect the lens from dust, scratches, and potential damage due to accidents. Additionally, they filter UV light that can cause a blue tint in your photos, as regular film is sensitive not only to visible light but also to UV. They are useful when photographing in mountains or at the sea or in any place with high UV radiation. They will filter the blue tint that usually blurs the background of your photo. They are also very useful when photographing in snow, as snow is an excellent reflector of UV light.