very evident on turning to spectacular lighting effects, and even the lighting of interiors illustrates a potentiality in light superior to other media.  For example, in a modern interior in which concealed lighting produces brilliantly illuminated areas above a cornice and dark shadows on the under side, the range in values is often much greater than that represented by black and white, and still there remains the possibility of employing the light-sources themselves in extending the scale of brightness.  Superposing color upon the whole it is obvious that the combination of “primary” light with reflected light possesses much greater potentiality than the latter alone.  This potentiality of light is best realized if lighting is regarded as “painting with light” in a manner analogous to the decorator’s painting with pigments, etc.

The expressive possibilities of lighting find extensive applications in relation to painting, sculpture, and architecture.  A painting is an expression of light and the sculptor’s product finally depends upon lighting for its effectiveness.  Lighting is the master painter and sculptor.  It may affect the values of a painting to some extent and it is a great influence upon the colors.  It molds the model from which the sculptor works and it molds the completed work.  The direction, distribution, and quality of light influence the appearance of all objects and groups of them.  Aside from the modeling of ornament, the light and shade effects of relatively large areas in an interior such as walls and ceiling, the contrasts in the brightnesses of alcoves with that of the main interior, and the shadows under cornices, beams, and arches are expressions of light.

The decorator is able to produce a certain mood in a given interior by varying the distribution of values and the choice of colors and the lighting artist is able to do likewise, but the latter is even able to alter the mood produced by the decorator.  For example, a large interior flooded with light from concealed sources has the airiness and extensiveness of outdoors.  If lighted solely by means of sources concealed in an upper cornice, the ceiling may be bright and the walls may be relatively dark by contrast.  Such a lighting effect may produce a feeling of being hemmed in by the walls without a roof.  If the room is lighted by means of chandeliers hung low and equipped with shades in such a manner that the lower portions of the walls may be light while the upper portions of the interior may be ill defined, the feeling produced may be that of being hemmed in by crowding darkness.  Thus lighting is productive of moods and illusions ranging from the mystery of crowding darkness to the extensiveness of outdoors.