"Light is the emblem of the highest good in many, perhaps all cultures. Its mystery has attracted some of the greatest minds in history from the author of the Book of Genesis to the concept of the speed of light as universal constant. In digital media, light is a medium of communication between humans, machines and the natural world, often employed to model events and wavelengths otherwise imperceptible to humans. At the same time, digital light is the heir to a millennial tradition of the employment, recording and representation of light in pre-digital media. This paper addresses the material aesthetics of digital light, including the restrictions of colour gamuts and redering software, in order to trace both the genealogies of contemporary light-based technologies, and to indicate where there is room for innovation and change."