His name may be synonymous with Shakespeare but Kenneth Branagh is at the helm of the epic adaptation of comic book tale Thor.

The annual battle of the summer blockbusters is about to commence with Thor proving the first competitor to throw its mighty weight into the box office ring.

The latest in a line-up of legendary Marvel Comic superheroes to be given a big screen adaptation, Thor promises to be an epic, adrenaline-fuelled 3D adventure.

At the helm is Kenneth Branagh, the man responsible for bringing Shakespeare's soliloquies to the masses in acclaimed film adaptations of Henry V, Much Ado About Nothing and Hamlet.

It's little surprise his appointment was met with a stunned silence from certain quarters of the fanboy network.

"I'm glad it's come as a surprise," chuckles 50-year-old Branagh, looking tanned and healthy beneath his greying hair.

Dressed in a tailored blue suit, he seems a bundle of bridled energy, popping mints and gripping on to his chair as if to stop himself flying out of the room like the hammer-wielding Thor himself.

"I think it's good for life to be full of surprises and as an artist it's nice to surprise yourself."

Branagh believes his involvement in Thor is nothing out of the ordinary though.

"It's got everything that I love - a hero who is headstrong and reckless, a young man who's forced to confront his past and deal with a complicated relationship with his father. I thought, 'Well, isn't that kind of the story of Henry V?'

"You could say I started in superhero films, the only difference in my previous ones is that people talk funny," he grins.

The larger than life character of Thor captivated the actor and director as a boy growing up in 1960s Belfast.

"It rained a lot in Northern Ireland and could sometimes seem greyish," recalls Branagh in pronounced vowels that belie his Northern Irish upbringing.

"The colour of the Marvel Comic covers would pop out from the book shelves and The Mighty Thor was the one I was always drawn to."

Strapping Australian actor Chris Hemsworth tackles the role of Thor, whose reckless actions reignite an ancient war.

As a result, he is banished to Earth by his father Odin (Sir Anthony Hopkins), where he is forced to live among humans, including astrophysicist Jane Foster (Natalie Portman), while his resentful brother Loki (Branagh's Wallander co-star Tom Hiddleston) plots universal domination.

Branagh readily admits the sheer scale of the movie both scared and excited him. His response was to embark on the journey with a three-prong approach.

"I definitely wanted to bring the story to earth," says Branagh, a decision which saw the cast and crew locate to New Mexico where they discovered springtime means snow, hail and gale-force winds.

He also felt it was crucial to bring humour and a lightness of tone to the story.

"We obviously took the job of trying to produce this piece of entertainment as seriously as possible, but we didn't want the film to take itself too seriously," he explains.

"We wanted the characters to have a sort of twinkle in their eye but not to mock them, so it was a delicate and difficult thing to do."

He hopes they've achieved it in playing with the simple yet archetypal idea of 'gods amongst men'.

"It creates dramatic tension, comic tension, and romantic tension if you produce something between two people of different worlds, like Thor and Jane Foster, and then break them up," says Branagh.

Perhaps the third prong stems from Branagh's role as an actor's director in that he wished to ensure the characters were as real and detailed as possible.

"I am surrounded by visual effects designers and costume designers and production designers who I know are going to deliver the 'spectacle', but I've been on pictures like this where that sometimes feels empty because the human dimension isn't as developed," he adds.

Branagh insisted on a lengthy rehearsal period, and continued to fine-tune performances throughout filming by insisting on numerous takes.

"Some actors think there's something wrong if you go over three takes but if they trust me, then we'll sculpt every single moment," he says.

It was a mantra that applied to veterans as well as novices, as witnessed during the big father-son confrontation scene in which Odin banishes Thor.

Initially, the central emotion was anger but Hemsworth has recalled the moment Branagh went over to Hopkins and said, 'Let this affect you. Be upset. I dare you'.

Afterwards, Hopkins put in the type of performance that had grown men on set crying, and caused the Silence Of The Lambs star to exclaim: 'He's good, isn't he, that Branagh'."

The director finds this story hilarious and enjoys a good chuckle to himself.

"Well, when you can tell someone like Hopkins that his character's heart must break in this moment, that the stakes are that high, you know as an actor he can take off another layer of skin and expose this vulnerable beating heart. It's that extra frisson that you get as an audience member."

Aside from the scale of the project, he was fully aware of the pressure posed by comic book purists, but his philosophy is simple: "You can't please everyone, you just hope you can entertain everyone," he says.

In fact, Branagh's first experience of a comic book convention, at San Diego's Comic-con, reminded him of his younger self "when I discovered I loved being an actor".

He adds: "I was suddenly travelling to Stratford-upon-Avon to watch plays, and getting copies of a theatre magazine called Plays And Players, in which a young man called Tony Hopkins appeared for the first time. I was obsessive, fanatical, and I've retained some of those feelings now."

A graduate of RADA, Branagh's stage work began in 1982's Another Country, which earned him an award for Most Promising Newcomer.

At the age of 29, he made his first venture into filmmaking with a production of Henry V, alongside his then wife Emma Thompson (they divorced in 1995 and he's now married to Lindsay Brunnock) which he both starred in and directed.

He was nominated for an Oscar in both the acting and directing categories for Henry V and continues to mesh these two careers.

His next project is My Week With Marilyn in which he'll star as Laurence Oliver opposite Michelle Williams's Marilyn.

"It sounds a bit corny, but I try and follow my instinct as to what will let me feel passionate and engage me," he says on whether he'll direct, act or do both, as he has on numerous occasions.

Not that he was tempted to combine the two crafts in Thor. "No," he simultaneously laughs and bellows.

"The scale of the picture meant it was impossible to imagine for a second I could do anything else but what I was barely hanging on my fingernails to do, which was to direct the thing.

"I've acted and directed before so who knows if I may do it again but I think in this case I would have been absolutely mad."

Extra time - The Thor facts

:: The Mighty Thor was introduced by the legendary writers Stan Lee and Jack Kirkby in 1962.

:: The character is based on the hammer-wielding Norse god.

:: The writers wanted to include a god in their comic book world and bring him down to earth as they do when Thor's father banishes him from Asgard.

:: Thor is a founding member of the superhero team The Avengers, which includes Iron Man and Captain America. The Avengers movie is scheduled for a 2012 release.