Only getting younger

In the hands of director David Fincher and screenwriter Eric Roth, “The Curious Case of Benjamin Button,” based on a short story by F. Scott Fitzgerald and opening Dec. 25, has been turned into a dazzling somersault of a movie that tumbles easily over decades, strange and swoony and romantic and sad. A baby is improbably born as an infant-sized old man, and as he ages and grows he actually gets younger.

The task of rendering the film’s aging effects was done by a mix of computer work and makeup techniques. Blending the two, and rendering the complicated process of aging characters played by Brad Pitt, Cate Blanchett and others without overwhelming the story, proved difficult.

“That was the challenge,” Fincher said. “You need to make sure that if people empathize with Benjamin it’s because his malady, or his curse, is something you believe in. But it’s also the cornerstone of where he’s going and why he behaves the way that he does. You don’t want to be taken out of the movie; you don’t want people looking at the neckline or the collar. You’ve got to be sure that stuff is seamless.”