3-D is everywhere, and it's good for more than just headache-inducing kiddie and horror flicks. I have my own doubts, given my poor depth perception and vulnerability to eyestrain. But the technology shows no sign of going away. Indiana University film scholar Barbara Klinger explores the seemingly contradictory elements of 3-D film's "illusion of depth" with the "invisible" style of directing associated with most Hollywood films—and discusses the "vital functions" 3-D can serve in films, from helping characterize style and genre to illuminating intertextual relationships with other films. —Zack Smith