BEVERLY HILLS, Calif. – “The Curious Case of Benjamin Button” is the Academy Awards heavyweight with 13 nominations, yet the shadow of Batman loomed large with the absence of “The Dark Knight” in the best-picture race.

An epic romance that earned a best-actor nomination for Brad Pitt and a directing spot for David Fincher, “Benjamin Button” was joined in the best-picture category Thursday by the Richard Nixon tale “Frost/Nixon,” the chronicle of gay-rights leader Harvey Milk in “Milk,” the Holocaust-themed drama “The Reader” and the rags-to-riches crowd-pleaser “Slumdog Millionaire.”

The Batman blockbuster “The Dark Knight” had picked up so much momentum from honors by Hollywood trade unions that awards watchers generally thought it would land a best-picture nomination.

“Benjamin Button” producer Frank Marshall said “it was a bit of a surprise” that his movie would not be competing with “The Dark Knight” for the top prize.

“The fact that ‘The Dark Knight’ did so well at the box office was probably a good thing and maybe a not-so-good thing,” Marshall said. “People tend to think films as successful as that are not well made, but certainly, ‘Dark Knight’ is exceptionally well made.”

As expected, “Dark Knight” co-star Heath Ledger earned a supporting-actor nomination on the one-year anniversary of his death from an accidental overdose of prescription drugs. If Ledger wins, he would become only the second actor to receive an Oscar posthumously, following Peter Finch, the best-actor recipient for 1976’s “Network.”

Josh Brolin, competing against Ledger with a supporting-actor nomination for “Milk,” said the acclaim for Ledger was bittersweet.

“It’s too bad, because every time I think of Heath, I’m split down the middle,” Brolin said. “I think of his performance. I think of the work that he’s done, and then the fact that this tragedy happened. It’s an uncomfortable situation, for sure, but it makes sense to me, because I thought he did a bang-out job.”

“The Dark Knight” picked up seven other nominations for technical achievement, among them cinematography and visual effects.

Yet it missed out on other major categories, including directing and screenplay. The directors and writers guilds both had nominated “The Dark Knight” for their top honors, while the Producers Guild of America nominated it for the year’s best film.

“Benjamin Button” leads a bold batch of best-picture candidates, among them Golden Globes champ “Slumdog Millionaire,” which came in second at the Oscars with 10 nominations.

Based on an F. Scott Fitzgerald story, “Benjamin Button” stars Pitt as a man aging backward toward infancy, caught in a tragic romance with the love of his life (Cate Blanchett) as she ages in the opposite direction.

The Oscars will be a family affair for Pitt, whose romantic partner Angelina Jolie has a best-actress nomination for the missing-child drama “Changeling.”

The honors for “Benjamin Button” include a directing nomination for David Fincher and supporting actress for Taraji P. Henson, playing the black foster mother who raises Pitt’s wizened white character.

“What I identified with on the first reading was, she understands love and how unconditional it is and should be. At the beginning of the film, she’s barren and can’t have children, then stumbles on this funny-looking creature on her doorstep,” Henson said. “She’s able to look past race and how odd he looked. She just knew he was a human being.”

Marshall and producing partner Kathleen Kennedy spent 18 years trying to make “Benjamin Button” and have been rewarded with a critical and commercial hit as the film crossed $100 million at the box office last weekend.

The film is “about perseverance, about life, about how you can control your own destiny. That’s kind of what happened here. Finally, a time came when all the right people came together at the right time to make the movie,” Marshall said. “Live your life forward or backward, we just hope you live it well. Now to have the audience respond to the movie has been thrilling.”

“Slumdog Millionaire” has found similar acceptance, its poor-boy-makes-good theme mirroring its success among fans and critics.

Shot on a modest $14 million budget, “Slumdog Millionaire” tells the alternately heartwarming and horrific tale of a street orphan in Mumbai whose pursuit of love carries him to triumph on India’s version of “Who Wants to Be a Millionaire.”

“Slumdog Millionaire” swept all four categories for which it was nominated at the Golden Globes, where it won best-picture over a field that included “Benjamin Button.” The film’s cast of unknowns was overlooked for acting nominations, but its Oscar categories include best-director for Danny Boyle and adapted screenplay for Simon Beaufoy.

“I just have to keep remembering that the film nearly went straight to DVD,” Beaufoy said, referring to a distribution hitch that nearly left the film without a theatrical run to qualify for the Oscars. “There was a week or two when it might never have appeared on a big screen in the United States, and the fact that it did, and Americans have taken it to their hearts is just fantastic.”

The best-picture field includes two 1970s tales of fallen political figures. “Frost/Nixon” stars best-actor nominee Frank Langella as the disgraced president in his battle of wits with TV interviewer David Frost. “Milk” features best-actor contender Sean Penn as the slain gay-rights pioneer.

Along with Langella, Penn and Pitt, best-actor picks are Richard Jenkins in the cross-cultural drama “The Visitor” and Mickey Rourke in the sports-comeback story “The Wrestler.”

Joining Jolie in the best-actress field were Anne Hathaway for the family drama “Rachel Getting Married,” Melissa Leo for the smuggling saga “Frozen River,” Meryl Streep for the Roman Catholic tale “Doubt” and Kate Winslet for “The Reader.”

Winslet plays a woman having a fling with a teenager who encounters her again years later as she is on trial for Holocaust atrocities.

At the Globes, Winslet was a dual winner, as dramatic actress for “Revolutionary Road” and supporting actress for “The Reader.” But the Academy saw Winslet’s turn in “The Reader” as a leading role, and one worthy of nomination.

It was Winslet’s sixth nomination. If she loses, she will tie the record of Deborah Kerr and Thelma Ritter for most nominations by an actress without a win. Stephen Daldry, a directing nominee for “The Reader,” suspects Winslet will be going home with an Oscar.

“I’m delighted for Kate,” Daldry said. “I think she did two astonishing performances in ‘Revolutionary Road’ and in ‘The Reader.’ Whichever one the academy went for, I think it’s her year. I think it’s her turn.”

The 81st Oscars will be presented Feb. 22 at Hollywood’s Kodak Theatre and broadcast on ABC.