The general aspects of design relating to the use of daylight and partificial lighting in art gallery and musuems are discussed. It is suggested that a natural lighting effect can still be achieved even if there is no link between the light illuminating of the object and the room. Whether electric lighting daylight or a combination is used a successfull design depends on an understanding of lighting properties and a realistic assessment of their potential. A chart compares the properties of natural and artificial light source (efficacy life, colour rendering, optical size, variation, control).