Director Ron Howard had a suggestion Wednesday for people riled by the way Christian history is depicted in "The Da Vinci Code": If you suspect the movie will upset you, don't go see it.

Howard's adaptation of Dan Brown's blockbuster was to open the Cannes Film Festival later Wednesday at a glitzy black-tie premiere. Beforehand, he answered questions about "Da Vinci" protests around the world — and also in Cannes, where a Roman Catholic nun wearing a brown habit kneeled in prayer at the base of the red carpet.

"There's no question that the film is likely to be upsetting to some people," Howard told reporters. "My advice, since virtually no one has really seen the movie yet, is to not go see the movie if you think you're going to be upset. Wait. Talk to somebody who has seen it. Discuss it. And then arrive at an opinion about the movie itself."

"Again: This is supposed to be entertainment, it's not theology," he said.

The book, and the screen adaptation, suggest that Jesus Christ was married to Mary Magdalene and fathered a child. One reporter asked the cast if they believed Christ was married.

Star Tom Hanks quipped, "Well, I wasn't around."

Christian groups as far away as South Korea, Thailand and India have protested the movie, planning boycotts, a hunger strike and attempts to block or shorten screenings.

In Cannes, a British nun, Sister Mary Michael, kneeled before a wooden cross at the base of Cannes' famous red carpet, where Hanks, Audrey Tautou, Ian McKellen and Paul Bettany were to greet fans before the premiere. Head bowed, she recited a rosary.

In Rome, Opus Dei, the conservative Catholic movement depicted as a murderous cult in "The Da Vinci Code," invited media to one of its vocational schools in a working class section of the Italian capital, to show off its work training young people to be mechanics, electricians and chefs.

"Soon this regrettable but fleeting episode will be forgotten," said Opus Dei spokesman Manuel Sanchez Hurtado. "Let us hope that its lessons about mutual respect and understanding are not."