When designing a stage lighting scheme, first consider the function that lights will play in the show. Consider elements such as what and who needs to be visible. Not all elements on stage have to be lit, but many stage designers believe that visibility affects the way an audience understands spoken words. In addition, consider the mood or atmosphere that the lighting should help achieve. Lighting plays an integral part in setting mood, so take into account how lighting affects the composition. Composition is the manner that the scene on the stage is painted, but with light, and an effective composition takes into consideration the time -- time of day and time period -- in which the scene takes place, as well as the amount of dimension the performers on stage should have.
Composition incorporates many factors, such as unity, harmony and contrast, which weave together to create a lighting scheme. Unity measures how the lighting fits in with the entire production, while harmony looks at how lighting relates to the rest of the elements, like the set or wardrobe. Contrast in lighting refers to the degree of difference between light and dark, which goes a long way in controlling the amount of dimension seen on stage. Little contrast will result in a flat look that is typically necessary for plays, while high contrast will make figures -- such as those in a dance or movement pieces -- appear more dimensional and shapely.
Light qualities can take nearly a hundred incarnations, but all beginners should know a few simple effects. Color is a simple concept in theory because lights can be used in nearly any color, but a designer must understand what each color means, how colors can combine or work in harmony. Intensity refers to the amount of light that hits one spot and is used to control contrast, mood and dimension. Distribution also refers to amounts of light, but more specifically how it is spread throughout the performance space. Movement is a very active process in lighting design because it often requires the physical movement of lights, whether they are following characters across the stage or something more flashy that resembles a rock concert.
Leading up to a performance, the process for stage lighting can be nearly as involved and rigorous as it is for the director, stage manager and performers. A brief step-by-step process includes: The lighting designer and their crew read through the treatment or script for the performance and stage cues; and they research elements like style, writer/composer, setting and the rest of the creative team. Pre-production meetings involve discussions about how to achieve mood, contrast and compositional elements. During run-throughs, the lighting team will take notes on the physical movements happening on stage as well as a rough outline of lighting cues -- which lights come up and when -- and those notes contribute to the overall lighting plan. The lighting plan should include the layout of specific lights, their function and intensity, and the final plan should be so complete that another lighting crew could recreate the production in the future.