MundoNiSchiz0o

Mariah Carey is known to fans as one of the most glamorous women in the world. But now they are about to see a different side of her in a gritty new movie.

Carey, 40, undergoes a transformation from her usual glam self into a dowdy social worker in the drama Precious, which was well received – as was Carey's performance – at its Cannes screening Friday.

"The only reactions from fans who have seen the trailer and twittered me have said the movie's amazing," Carey tells PEOPLE. "No one has said, 'Girl I can't believe you are there with those dark circles under your eyes and wearing a wig and looking nasty.' No one went that far."

Her husband, Nick Cannon, has been equally positive. "My husband's response was over-the-top supportive and amazing. It was not like, 'I can't believe you let yourself look like that in the movie.' "

Precious is based on the book Push by Sapphire and tells the story of a young girl growing up amid terrible domestic abuse in Harlem. It will be released to the public on Nov. 6.

Peel Away Layers
Carey told a small gathering of press at Cannes, "[The book] is intense and it is life-changing. I said, 'Let me peel layers away of who the world thinks I am, of who I personally think I am as a performer, as anything, and become, truly become, this woman who has a large responsibility.' "

Of her character, Carey said: "She is the audience and is that shocked person who hears what goes on and has to kind of bare her soul because she's hearing something that is so horrific that she's never heard before. There's a creative side of me that needs to do work like this."

Carey was chosen for the part at the last minute. "I thought how bold would it be to cast Mariah," says director Lee Daniels. "If she could dye her hair, put on a wig, take off the makeup, darken under the eyes, I believed she would begin to give me her soul. And she did."



The result, according to singer Lenny Kravitz, who plays a nurse in the movie, "was beautiful."

New Star
In addition to Carey's transformation, the movie's other surprise is its breakout star Gabourey Sidibe, who plays the leading role. It is her first movie – and she's loving the attention in Cannes.

"I'm having the most fun ever, more fun than I imagined myself having," she told PEOPLE. "This is completely glamorous. This is nothing like I thought my life would be heading towards."

More roles are likely to follow. "I just got my second movie offer. It's a little too soon to talk about it but I am really excited about it because I'm an actress now."