Stanley McCandless was a lighting designer and Yale University professor and is recognized as the father of modern lighting design because of his McCandless Method -- a system that would subsequently become the basis for theatrical lighting design. This method of illumination divides the stage into nine separate areas for the actors. Two lighting fixtures accompany each of these areas. Each light has a different hue to provide contrasting tones to the area. The McCandless Method highlights the actors first and the background second.
Single source lighting involves illuminating the entire stage from one point of origin. This technique is for the most part impractical. For starters, this technique requires an extremely high wattage output. In addition, single source lighting can't keep the light confined to the stage. This method also requires a large theater, because the lighting fixture has to be a considerable distance from the stage.
Using multiple sources is done a lot because it allows greater freedom and operational mobility. Using multiple sources of light also allows the designer to cater to the convoluted nature of the text and the performances by using the numerous lights to complement the textures and layers of the production itself. Many theaters average between 400 and 500 lighting fixtures in the house. Typically, each of these fixtures can dim at the designer's discretion.
The primary focus of attention for most lighting designs is the actors or performers. The actor areas receive preferential treatment. The audience tends to watch the people on stage first; this fact accounts for their place at the top of the lighting food chain. After the actors comes blending. Blending is the attempt to illuminate the areas and objects near the actors to create a good contrast. Lastly is the background. Background lighting refers to the farthest areas downstage, usually the backdrop or back wall depending on the set.