As soon as pre-production starts on a show, the lighting designer will be given a copy of the script. She will also receive a diagram of the configuration of the stage and be shown what the set design looks like. Finally, a list of available lighting instruments and technology will be provided. It is then up to the lighting designer to create a basic design and lighting plot for the production that shows how the show will be lit, and how the lights will be hung.
Depending on the theater, a production may either require a full lighting hang or a re-focus of permanent lights. The lighting designer works with the technical staff to make sure that all lights are in the required positions and focused on the appropriate areas. This work also includes installing gobos and gels into the lights to achieve any desired effects or colors in the lighting. Finally, the designer tests the lights and design to ensure everything is working properly and looks correct.
All technical staff within a production exist to help the director realize his vision for the play. The lighting designer has to work with the director to come up with creative ways to light certain situations. For instance, a director might decide partway through rehearsal that he needs a spotlight in a certain area, or a strange light that emerges from underneath or inside a set piece. The lighting designer needs to create solutions to these problems.
In some smaller regional theaters, the lighting designer will also be the lighting operator when the show is running. In other larger theaters, there may be a separate operator. In either case, the lighting designer has to help during tech weekend to ensure that the show is lit smoothly. This might include refining and designing cues for themselves, or helping the lighting operator see how the cues need to be implemented to light the show according to the director and designer's vision.