Lamps and lighting

There is now a wide demand for the provision of high-quality visual environments and consequently lighting engineers need to examine closely the numerous interacting aspects of human activities. This paper reviews the characteristics of the human visual system and how these affect visual performance under different lighting conditions. The way in which the techniques that are used to convert electrical energy to visible radiation influence the quality of the radiation for lighting purposes is discussed and the paper concludes by linking the properties of several families of lamps to the main lighting appliances.