British star Clive Owen has specialized in playing macho men in two decades of movies and television: tough, taciturn and unshaven, with long stares from smoldering gray-green eyes.

But Owen, nominated for an Oscar for his role in the 2004 drama Closer, is trying on a new persona in his latest film, The Boys are Back, playing an inept father who suddenly finds himself a grieving single parent to an equally grieving son.

I haven't done a film like this before and parenting is a big part of my life. It was a challenge to explore, and something that I thought was very well written -- the ups and downs of parenting, Owen said in an interview.

The movie, which was featured at the Toronto International Film Festival and opens in U.S. theaters on September 25, includes a lot of shots of Owen looking lost, and a lot more where he is clearly clueless about coping with a 7-year-old whose mother has just died.

Set in Australia and Britain, it follows a period in the life of sportswriter Joe Warr, whose ranch house fast turns into a pigsty as Warr brings his just say yes philosophy of life to the caring of his young son.

The two are joined by Joe's older boy from England, and what plays out on screen is an exploration of parenting and father/son relationships that Owen said is more true to real life that what audiences tend to see on film.

Very often when you see families it's all perfect and neat, and parenting isn't like that. You do have constant negotiations. Things are ever developing and ever changing, and you constantly have to evaluate how you deal with your kids.

Owen has two daughters, aged 10 and 12, with his wife, Sarah-Jane Fenton, and he said this was one of the first of his movies they've been able to see. His other films like Closer, or Spike Lee's popular Inside Man were not quite suitable.

They feel very part of this one because they were in Australia for a few weeks, he said.

The star, who has played a range of characters from the adventurer Sir Walter Raleigh in Elizabeth: The Golden Age to man-on-the-run Theo Faron in science fiction film Children of Men, is not immediately turning back to those tough roles.

In fact, he said his next venture will be another family movie, but a darker, different one. It's a very upsetting family drama, he said, without giving details.

Meanwhile, a sequel to the 2006 box office hit Inside Man is also in the works, he said.

That film, set in New York, stars Owen as the robber who plans the perfect bank heist, with Denzel Washington and fellow Brit Chitiwel Ejiofor as the cops who try to outwit him.