Functions of Stage Lighting
Jeff's Note: While most textbooks teach that there are four functions of stage lighting, I believe there are seven:
  1. Visibility: If the audience can't see the actors, everything else the lighting designer does is a waste of time. Studies have shown that visibility affects our ability to understand spoken speech. This doesn't mean that the audience must see everything all of the time; a German director named Max Reinhardt once said that, "The art of lighting the stage consists of putting light where you want it and taking it away from where you don't want it."

  2. Mood: (or "atmosphere") "Mood" is the evocation in the audience of the appropriate emotion. Many designers err in paying attention to mood to the point where visibility is sacrificed.

  3. Composition: The act of painting a picture, in this case, with light.

  4. Plausibility: Sometimes called "realism", but that's not always accurate, since not all plays - and certainly very few ballets, modern dance pieces, and operas - are realistic. It's the same quality that Stephen Colbert refers to as "truthiness".

  5. Reinforcement: What are we reinforcing? Everything.

    • We reinforce the playwright's text: In A Midsummer Night's Dream, Puck has the line, "And yonder shines Aurora's harbinger," meaning the dawn. The lighting designer can reinforce this by providing the first rays of dawn.

    • We reinforce the work of the set and costume designers:
      • We might use colors that flatter or complement those used by our colleagues.

      • If the sets and/or costumes are sculpted and lush, we might light them so as to highlight their 3-dimensionality.

  6. Revelation of Form: Decide on the level of 3-dimensionality you want the audience to see. In some productions, you might want a "flat" look; in others particularly in dance you might want a more sculpted look. A case could be made that revelation of form is part of composition or mood; however, it's important enough (in some productions, at least) to be a stand alone function.

  7. Punctuation: The blackout at the end of a climactic musical number! The slow fade to black....

  8. Telling the Story: Advancing the narrative, through use of the other seven functions. Note that some productions, notably (but not exclusively) in modern dance and ballet, do not have a "narrative," per se.

Judy has a different list:
  1. Selective visibility: illumination and focus.

  2. Indication of time and place (and any other realistic details necessary). (if not given in the play, it is often a good idea to invent them.)

  3. Mood and atmosphere (often best conveyed through the realistic details you have invented; these are generally more specific and interesting than "blue for sad".)

  4. Creation or emphasis of rhythm and punctuation.

  5. Heightening effect of other visual elements of the production: set, costumes, mise en scene.

  6. Integrative function: brings all other aspects of the production (dead scenery and live actors) and unites them into one world.

  7. Just aesthetics - often there is a show where you don't have much to do besides illuminate, and another useful aim is to try and make it look prettier or more visually striking than it would have without your lighting, thus compelling audience attention more strongly and heightening the theatrical experience. It might be a simple comedy or ballet, and you might just want to frame it in nice color or throw some gobos on the cyc.

  8. To aid in conveying whatever message you, the director, the other creative artists are trying to get across. An example might be that you're doing Othello and the idea is to create a feeling of the evil in the world overcoming the forces of good, so you (and the set designer hopefully, but not always) would strengthen that impression with light by having everything generally bright at the start and closing in to more isolated areas with dark outside as the play progresses.

  9. Helping the actors! Actors are generally happy that the stage lighting shuts them off from the audience in a different world, but sometimes they may need extra help - it could be be as simple as some low-intensity light to help them find their way in the dark. Actors blinded by sidelights may be helped by having faint light on the floor; this is an absolute necessity for dancers en pointe.

Note that two designers who had never met and who work 8,000 miles away from each other have developed strikingly similar variations. Also note the differences; in art, there is rarely only one correct approach. If your instructor teaches a different list of functions and qualities than the ones on this site, s/he is right...but so are Jeff and Judy.