My Lighting Design professor had a very wonderful theory of how her design should work in dialogue with that of the other designers and with the text of the story; "lighting should evoke an environment", she said.
This can be applied to all design factions too. It is better to imply to an audience the world of the play and let your suggestions play upon their imagination rather than striving to recreate a perfect world on stage. As Brecht said (and I'm paraphrasing here) "I'm all for realistic theatre. But the truth is I'm sitting in a theatre." No matter how perfect the theatre technology, no matter how big your budget, and no matter how good the special effects are, the realism of any theatrical moment is destroyed by the fact that there is an audience present; it's not real. Let film try to conquer realism as is so expertly does and allow theatre to flourish in what it does best.
Theatre is a medium of imagination and inspiration. It is a platform where a stick can become a sword, a blanket a cape, and a piece of blue fabric a vast ocean. The audience is willing to go where ever you are bold enough to take them. It's just like the imaginary games you played as a kid where as long as you said the rules of the imagination (hey everyone let's get on this space ship and fly) everyone had to go along with you.
Shakespeare is grand at doing this - he describes his environment in words and the audience has to go along with it. Mary Zimmerman has made it her brand. Sarah Ruhl is a master. Charles Mee is an expert. Let's find more and more playwrights who challenge their designers to be creative and imaginative and in turn challenge their audiences to do the same.
Happy Birthday: Wil Wheaton (b. 1972)