The Functions and Qualities of Light

1. What are the functions, or purposes, of light?

1. Composition: The creation of a series of inter-related images which assists the director in presenting his interpretation of the play.

2. Visibility: The responsibility of the designer to provide enough light for the audience to see the performer.

3. Modeling: The use of high light and shadow to reveal the three dimensional form of the performer.

4. Focus: The designer's use of contrast to focus the audience's attention.

5. Information: The use of light to establish the time of day, the season, and the location of the play's action.

6. Mood: The reflection of the ever changing emotional content of the play. It is, in a way, very close to the style of production.

2. What are the controllable properties, or qualities, of light?

1. Intensity: The amount of light reflected by the performer and the background.

   Factors determining the intensity of the light:

   1. Type of instrument
   2. Wattage of the lamp
   3. Length of throw
   4. Size of the pool of light
   5. Color of the gel
   6. Amount of electricity reaching the lamp (dimmer level)
   7. Reflective quality of the make-up, costume and setting

2. Color: The color of the light reflected by the performer and the background.

   Factors determining the color of the light:

   1. Color of the gel
   2. Color temperature of the lamp
   3. Intensity of the lamp (dimmer level)
   4. Color of the costume, make-up and setting

3. Direction: The direction (or angle) of the light determines the length and location of the shadows cast by the performer and the three dimensional props around him.

   Factor determining the direction of the light: Where the instrument is placed.

4. Distribution: The distribution of light determines which part (or parts) of the stage will be lit.

   Factors determining the distribution of the light:

   1. Where the light is focused
   2. The type of light
   3. The focus (spot or flood) of the light
   4. The use of "masking" devices: shutters, barn doors, and top hats
   5. The direction (angle) of the light

5. Texture: Texture is the quality of the light-- its diffusion or clarity. Does it have a soft edge or is it hard edged? Is the field of the light smooth, diffuse, or is it heavily textured?

   Factors determining the texture of the light:

   1. The type of light
   2. The use of diffusion gel
   3. The use of a gobo

6. Movement: Movement is any change in the intensity, color, direction, distribution, or texture of the light. Such a change is a light cue.

3. What is the relationship between the functions and the properties of light?

Composition is the end product of the lighting design and is influenced more by the other functions than by the controllable properties of light.

Visibility is determined by the intensity, color, and direction of the light.

Focus is determined by the intensity and distribution of the light.

Modeling is determined by the direction of the light.

Information is presented by the intensity (Day is bright and night is dark), color (Day is pale yellow and night is dark blue) and direction (Sun light rises stage left and sets stage right) of the light.

Mood, or tone or style, is determined by the intensity (Comedies are bright), color (Comedies are warm), direction (Comedies have few shadows) and distribution (Comedies are evenly lit) of the light.