It's the Australian actor's debut as a feature film director and, as if that wasn't pressure enough, Baker also felt the burden that comes with putting a cherished story on to the big screen.

"For the years that it took to make the film, people would come up to me all the time and say 'you're making a film of that book Breath, that's my favourite book. Don't stuff it up'," Baker told AAP in Sydney.

"So I'd like a dollar for every person who said that to me."

The pressure has been relieved somewhat as Baker has been receiving positive reviews since the film premiered at the Toronto International Film Festival, and it will soon be released in Australia.

Set in the 1970s, the film follows two teenage boys, Pikelet and Loonie, played by newcomers Samson Coulter and Ben Spence, who are taken under the wing of an enigmatic older surfer called Sando (Baker).

"There was always Sando figures in my life and they were all well intended but not everybody's a perfect mentor, a perfect role model," Baker said.

Largely shot in the WA coastal town of Denmark, the film indulges in long dramatic shots of the ocean, as surfing takes centre stage as much as the boys' coming-of-age does.

But Baker also worked at portraying Winton's themes of masculinity and the expectations young men often put upon themselves, and how the writer subverted that expectation through this story.

"In the 70s we had this Australian macho archetype and in a sense we set the frame up for that. We establish that in this film and then we subvert it," he said.

"The bravest thing that this kid does is not heroic in the sense that he doesn't conquer another person or his fear of the ocean. The bravest thing he does is he stands on his own two feet."

There's something about that bravery, rejecting that expected machismo, that's already started to touch a nerve with the audience, as Tim Winton noted after several of the film's early screenings.

"In Albany, Denmark and Perth, the three screenings, you'd stand there and you'd realise there were lots of pale faces but some of them were shining and they were men in their 50s and 60s and they were crying. And that's not generally a common cinematic experience for men of that age," Winton told AAP.

"Simon has made a beautiful film."

* Breath releases in Australian cinemas on May 3.

Australian Associated Press