There are a number of excellent articles over on the website of the American Association of Community Theatre.
This is the fifth in a series of extracts from those articles and a link so that if you want to read more you can get to the entire article.
The fifth one is about the role of The Lighting Designer.
Lighting designers know how to make the best use of the subtle and powerful medium of light, creating effects that can be changed at will to match the mood of the action.
At its most basic, stage lighting functions to make the actors and their environs visible to the audience. But it can also be used to:
Evoke the appropriate mood
Indicate time of day and location
Shift emphasis from one stage area to another
Reinforce the style of the production
Make objects on stage appear flat or three dimensional
Blend the visual elements on stage into a unified whole
The Designer's work
The lighting designer begins by reading the script to be produced noting the type of light it calls for in each scene.
Designer and director share their ideas about how light could be used to enhance the production concept at their first meeting. Early meetings with the set designer are also important because the set and lighting designers must collaborate on how to achieve the desired "look" for the play. The plan for the set may influence the placement and direction of the necessary lighting instruments, so flagging any potential problems in this area as early as possible makes sense.
Lighting designers attend rehearsals to get a feel for the lighting cues and to plan how to light the actors as they move from place to place on stage. When the blocking is set, the lighting designer can start to work out which lighting instruments will be used and where each one will be located.
The complete article can be found here.