Michael Keaton and Emma Stone talk about Birdman – the dark comedy with nine Oscar nominations

Alejandro González Iñárritu's Birdman revolves around a man in pain. This time the washed-up superhero star Riggan Thomson’s (Michael Keaton) bid to gain credibility is leavened with dark humour and satirical wit.

Birdman director Alejandro González Iñárritu, above centre, is up for an Oscar along with the actors Michael Keaton, Edward Norton and Emma Stone. Twentieth Century Fox

The last thing anyone expected to hear associated with Alejandro González Iñárritu was comedy. A purveyor of darkness with films such as Babel, 21 Grams and Amores Perros, the Mexican miserabilist has cut his cinema­tic cloth from the agony of the human condition.

True to form, his latest feature, the multi-Oscar nominated Birdman or The Unexpected Virtue of Ignorance, revolves around a man in pain. However, this time the washed-up superhero star Riggan Thomson's (Michael Keaton) bid to gain credibility is leavened with dark humour and satirical wit.

Having served-up a series of dramas that he likens to generous portions of “spicy Mexican chilli”, Iñárritu says it was time for “a dessert”. He left his “comfort zone” and discovered laughter in the process. “That’s been a great relief,” he says.

Birdman is full of experimentation and breaks decisively away from the interconnected stories and non-linear narratives of the director's early work. Collaborating closely with the innovative cinematographer Emmanuel Lubezki (Gravity), Iñárritu shot Birdman as a series of long takes that float through the front and rear of house at the theatre where Riggan is rehearsing his play. Put together, they create the feeling of watching one continuous, long piece.

The precise choreography required to make this work was challenging for everyone. "I didn't really find it nerve-racking, though," says Edward Norton, who in real life lacks the pretentiousness of his Birdman character, Broadway thespian Mike Shiner. "It's not Gaza. Nobody's dying. It's just making a movie. And it was like a really fun, grand game."

Things did sometimes go wrong. “We got towards the end of one scene and I walked into the camera,” says Amy Ryan, who plays Riggan’s ex-wife. “We were so close, almost had it, and I crashed into it. On the second take it happened to the boom operator. We had a wonderful little, ‘all right, it’s not just me’ moment.”

Keaton is hardly ever off-screen. But, despite “shouldering such a heavy load”, says Ryan, “I never saw him in a sour mood or lose it.”

Although some will wonder whether there is an element of biography in Keaton’s casting, the man who was Batman – under the guidance of Tim Burton, about 25 years ago – insists that unlike Riggan, he doesn’t feel haunted by his comic-book alter ego. Meanwhile, Emma Stone, who plays his daughter, claims she “never identified Michael Keaton with being Batman”.

"I have just always seen him as a brilliant actor," says the Spider-Man star. "Obviously, he's not playing himself in this. Obviously, he doesn't feel the need to come back and write and direct and star in a Broadway play."

Even before the Oscar nominations (including ones for Stone, Norton, Keaton and Iñárritu) were announced, however, Stone noted that Birdman was already making people "realise just how brilliant [Keaton] has always been".

His career is likely to soar skywards again on the back of Birdman. Even so, you get the sense that Keaton isn't a man who gets overexcited about such things. Batman and the global recognition that came with it were "pretty cool", he says matter-of-factly.

“I tend to work on living in the present and I just go from gig to gig,” he says. “But I’m human, so the things that follow me around are things that I look at, professionally, and go: ‘Oh, I really wasn’t very good in that movie.’ That’ll follow me around a little bit. But, frankly, even that doesn’t follow me around for very long.”

Still, “Michael Keaton: Oscar winner” must have a nice ring to it.