Guess who? Mariah Carey in Precious....couldn't recognize her

Mariah Carey glam at Cannes, but dowdy in Precious | Movies | News.com.au

IT'S Mariah Carey as you've never seen her before.

The singing star who has refused to travel without an army of beauticians and once admitted sleeping with 20 humidifiers around her bed ditches the glamour for a movie role.

And the switch from diva to dowdy could be her best move yet, with the film, Precious, already winning critical acclaim.

The 40-year-old sports a scruffy hairdo and unflattering blouse to play a social worker in the movie.

Set in Harlem in 1987, Precious tells the story of an overweight, illiterate girl who becomes pregnant with her second child at the age of 16 after she is raped by her father.

Gabourey Sidibe plays the title role after director Lee Daniels discovered her on the streets of New York.

The film - adapted from Push: A Novel - premiered at the Sundance Film Festival in January where it won the Audience Award and Grand Jury prize for best drama.