A prism is a transparent optical medium, usually made of glass or plastic, that can bend (refract) light at varying degrees depending on its wavelength. This property allows prisms to separate white light into its component colours, creating a spectrum, or to redirect and manipulate light paths in optical systems.
In photography and optics, prisms are used in cameras, viewfinders, binoculars, and other imaging devices to correct orientation, direct light, or enhance colour effects. Understanding how prisms interact with light is essential for lens design, optical engineering, and achieving precise image reproduction in both analogue and digital photography.