Walk outside. Take a look at your surroundings. Think about what you see. Can you describe it in terms of light and shadow? You might see a brilliant blue sky and the dappling of light and shadow as it falls on the sidewalk in front of you. You might notice the pools of light created by streetlights and how the people around you float in and out of light and shadow. Do you see your world differently when you think about the light all around you? How does it change your perception of your surroundings?
Lighting a stage allows the audience to see the world of the play, but it is much more than illumination. The lighting designer must be something of a magician, revealing what must be seen and hiding what needs to be hidden. He or she has the ability to subtly influence the perceptions of the audience and to dramatically transport them from one magical place to the next. Time of day can slowly change over the course of a play or you can go from a scorching desert to a cold, dark castle.