Director Steven Soderbergh's new movie Unsane is premiering at the Berlin International Film Festival next month (February).

Before its premiere, Straits Times readers can get an exclusive peek at the American film-maker's new project with this trailer.

Unsane stars The Crown's Claire Foy - in a role as far from the decorous glamour of the Netflix series as you can get - as a woman who is committed to an insane asylum.

Beyond the usual film fest bait and starry cast, Soderbergh's latest project has an unusual twist: The film is shot entirely on iPhone.

The 55-year-old director is no stranger to new technologies. He was an early champion of high definition video and favours shooting with the RED camera, a professional digital cinema camera.

Still Soderbergh, who heralded the indie film-making boom in America with his 1989 debut sex, lies and videotape, has a proven track record. He may have announced his retirement from film-making in 2013, but it looks like the maverick is back.

Unsane opens in Singapore on April 5.