With three of this year's Best Picture Oscar contenders having been adapted from books, Penn State film professors said adaptations are most successful when they strike a balance between originality and sticking to source material.

A good adaptation incorporates "being true to the book as closely as possible while making changes that condense the story but maintain the overall feeling and character," professor Maura Shea said.

The Curious Case of Benjamin Button, The Reader and Slumdog Millionaire are book-to-film adaptations up for Best Picture at Sunday's Oscar ceremony, and other book adaptations have been nominated in other categories this year.

Monica Yates Shapiro, daughter of Revolutionary Road author Richard Yates, said screenwriters remained true to her father's vision when writing the script for the Oscar-nominated film.

"From my point of view, they couldn't have honored it more beautifully," she said. "The way it looks and feels is just what you envision."

But film professor Jeanne Hall said she believes in taking creative license with film adaptations.

"I don't think you have to have any fidelity to the original," she said.

Vikas Swarup -- who wrote Q & A, the novel Slumdog Millionaire is based on -- said he understands books and films are different mediums and should not present a story exactly the same way.

"I think a film should not be a literal translation of a novel," Swarup said. "The screenwriter should have the luxury of putting in some of his own elements."

Both Shapiro and Swarup said they had little say in the film adaptations.

"I would've messed it up," Shapiro said, adding she preferred not being involved with the screenplay because she didn't know enough about the process.

Swarup said he did not directly take part in the adaptation, but had some creative control when it came to the content. The screenwriter told him, "a book is a book and a film is a film, so we'll have to change some of the stories," he said. But he said he felt the film captured the book's tone.

"A novel already has a fully fleshed-out story and a filmmaker then has the liberty of picking and choosing elements that they think are best suited for the film medium," he said.

Film professor Rod Bingaman said audiences often complain movies aren't as rich as the books.

Swarup added he thinks books often have more depth.

"The film requires a certain suspension of disbelief, which every film does, but in a book you have to be completely logical."

Though Swarup, an Indian diplomat who lives in South Africa, hasn't seen many of this year's best picture nominees, he said he's hoping for the film based off of his novel.