Keaton's Birdman Opens Venice Film Festival

Michael Keaton's film about a washed-up action star has opened the world's oldest film festival in Venice.

Alejandro Gonzalez Inarritu's Birdman had its first screening for journalists ahead of a gala to be attended by the director, Keaton and stars Edward Norton and Emma Stone.

Keaton, best known for playing Batman, plays an over-the-hill actor once famous for playing a superhero. He is now struggling to put on a Broadway play.

Early reaction to the genre-blending film was positive. The Daily Telegraph called it "grand, spectacular, star-powered cinema".

Variety labelled Keaton's performance "the comeback of the century".

The movie is one of 20 competing for the Golden Lion at the festival. Last year's Venice opener, Gravity, went on to win seven Academy Awards.

Other hotly-awaited world premieres include Good Kill by New Zealand's Andrew Niccol, starring Ethan Hawke as a drone operator in Afghanistan.

David Gordon Green's Manglehorn, with Al Pacino as an ex-convict-turned-locksmith with a broken heart, is also featuring at the festival.

French film composer Alexandre Desplat heads up the main jury at the festival, which runs until September 6.

Desplat's works include the scores for The King's Speech and Harry Potter And The Deathly Hallows.

Festival director Alberto Barbera brushed off criticisms that this year's event was light on Hollywood stars.

He said the aim of the organisers had been to create space for high-quality, innovative flicks which risk falling through the cracks.

"I have nothing against glamour, but it cannot be the only component in a festival. The idea is to explore cinema today in all its complexities," he said.

The festival is bringing a new generation of artists to the Lido this year with its first edition of a gap-financing market.

The market matches young producers in need of funds with investors and distributors - as well as Final Cut, which showcases finished films from Africa and the Middle East.

This year's only documentary in competition is The Look Of Silence, Joshua Oppenheimer's follow-up to his acclaimed 2012 The Act Of Killing.

The documentary sees Indonesian genocide survivors confront the killers of their brother.

Out of competition slots have gone to US director Peter Bogdanovich's She's Funny That Way, a comedy starring Owen Wilson and Jennifer Aniston, as well as American Lisa Cholodenko's four-part HBO series Olive Kitteridge, starring Bill Murray.