The 75th anniversary of the Venice Film Festival has opened with the screen adaptation of Ian McEwan's novel Atonement, starring Keira Knightley and James McAvoy.

The pair joined director Joe Wright and co-star Vanessa Redgrave on the red carpet for the gala opening of the prestigious event, alongside Sleuth director Kenneth Branagh and stars Michael Caine and Jude Law.

Atonement – which is already creating an Oscar buzz – is tipped to win the Golden Lion award for Best Film against Sleuth, legal thriller Michael Clayton, starring George Clooney, and Ken Loach's It's A Free World.

Bob Dylan biopic I'm Not There, featuring Richard Gere and Cate Blanchett, and Peter Greenaway's Nightwatching, starring Martin Freeman, are also in contention.

Ang Lee's new drama Lust, Caution - which sparked controversy after festival organisers noted that it was made in "Taiwan, China" - will also be unveiled at the event.

All but six of the 57 films shown at the festival will be world premieres. The winning film and awards for best director, actor and actress will be unveiled at the event's climax on September 8.