A lens flare is a visual artifact caused by light scattering, or flaring, in a lens system. This can happen through light scattered by the imaging mechanism itself, for example through internal reflection and forward scatter from material imperfections in the lens. Lenses with large numbers of elements such as zooms tend to have more lens flare, as they contain a relatively large number of interfaces at which internal scattering may occur. These mechanisms differ from the focused image generation mechanism, which uses rays that are from the reflection of light on the subject to be imaged and propagating along the intended paths in the lens system.