Lighting and visual perception

A brief account of modern views of visual perception is given, related to our knowledge of lighting. There is evidence for thinking that some part of the phenomenon known as brightness constancy is the result of the structure of the nervous system. It is deduced that brightness constancy will hold most accurately where contrasts are low and is liable to break down when they are high. This implies that in lighting for display and dramatic effect contrasts should be increased. The physical implications of this conclusion are developed in three appendices. The results are consistent with current practice.