What is the purpose of key lighting in stage production?

The purpose of key lighting in stage production is to highlight the main subject. Key lighting is the primary source of illumination and is strategically positioned to define the most important part of a scene. By directing light onto the main subject, it draws the audience's attention and adds depth and dimension to the performance. This technique enhances the overall visual storytelling and helps convey emotions, actions, or character traits.

The other options represent different aspects of lighting but do not align with the specific function of key lighting. For instance, creating a soft background light refers more to fill lighting or background lighting techniques rather than key lighting. Eliminating shadows completely might be a goal of various lighting setups, but key lighting often intentionally creates shadows to add depth. Providing ambient light for the audience pertains to overall stage illumination and audience visibility, which is not the primary role of key lighting.