The 23-year-old "Harry Potter" actress stars in Sofia Coppola's "The Bling Ring," which premiered Thursday at the French Riviera festival. The British actress plays a celebrity-obsessed, thickly accented Los Angeles teenager who, with a group of friends, burgles Hollywood stars such as Paris Hilton and Lindsay Lohan.
At Cannes, Watson told reporters that while she remains proud of her work on the "Potter" films, they now feel long ago.
"I'm not trying to run away from it," she said. "I've just had an amazing three or four years. I'm really re-enjoying having the chance to transform into new roles and work with new creative people."
"The Bling Ring" is based on a Vanity Fair article about the true story of teenagers who robbed celebrities like Paris Hilton and Orlando Bloom while they were out at premieres and other events. The character Watson plays, Nicki, is modeled on Alexis Neiers, who starred in the reality series "Pretty Wild."
Watson said she watched American TV shows like "The Hills," ''Keeping up With the Kardashians" and "The World According to Paris" to prepare for the role.
"It'd be very easy for Nicki to feel like a parody," Watson said. "Somehow I had to understand and empathize with her and that was really biggest challenge, second to getting the accent down. It's quite a specific dialect."
Since the "Harry Potter" films concluded in 2011 with the second part of "Deathly Hallows," Watson has gravitated to more adult films, including last year's coming-of-age tale "The Perks of Being a Wallflower" and Darren Aronofsky's Biblical epic "Noah," which recently finished shooting. She also makes a cameo as herself in this summer's "This is the End," an apocalyptic comedy.
"For Emma, it was, I think, really interesting to see an actress that you've seen in other things really transform into a completely difficult character," Coppola said.
Young actors often treat Cannes as a coming-out-party, a place to introduce themselves on a more artistically-minded stage. Watson shined with enthusiasm for her experience with the improvisation-friendly Coppola.
"I could work in a way that was a lot more loose than I was used to," said Watson. "I'm used to really having to stick to my lines because a lot of people know them by heart."