Hollywood is a strange creature: an often unyielding machine where, in the modern economy at least, box office dollars are more important to studio chiefs than indulging the whims of artists and dreamers.

And yet, in its midst, stands the legendary Steven Spielberg, who at 69 years old is surely afraid of nothing and has crafted a powerful legacy as a storyteller.

"I sometimes have to swim with the sharks, which I actually did once," he says, referring to one of his earliest and influential works, the 1975 thriller Jaws which – against the odds – made almost half a billion dollars from an extremely modest $US9 million budget. "It turned out pretty well."

Since then, Spielberg's name has appeared alongside a vast array of now iconic films. They range from the profoundly human and personal (Schindler's List and Saving Private Ryan), to science fiction (Close Encounters of the Third Kind and E.T.) and, in the Indiana Jones films, a series of post-Biggles "boy's own" adventure stories.

They are, he adds, very different from each other.

"In the sense that they give me the opportunity to be Walter Mitty. I get a chance to daydream, to imagine I'm in different places at different times," he says. "Some of them don't bear much of a physical resemblance to each other but there's always going to be some thematic thing that runs through them."

What those themes are, however, he leaves for the film's audiences to determine.

"I leave it to you to figure out what the themes are," Spielberg says. "I'm not conscious of that and I don't make choices because it's similar thematically to something that's in my conscious mind."

He does, however, admit to a lot of father/son stories.

"I've always maintained that's a subconscious choice not something I do on purpose, but I find myself not able to get away from it," he says. "At the same time I find it so much fun to be able to indulge my fantasies and just do an adventure one year and a very deeply personal story in the next."

Sophie (Ruby Barnhill) has her first encounter with the giant in Steven Spielberg's The BFG. 

In , Spielberg is charged with constructing a fantastical world based on the imagination of one of the world's greatest children's authors, who also wrote Charlie and the Chocolate Factory and Matilda.

Dahl, who died in 1990 at the age of 74, was one of the greatest storytellers in modern history, Spielberg says. "Dahl understood drama," he says. "He was a good dramaturgist, but so was Walt Disney who embraced darkness to be able to emphasise the light. Dahl knew this, too.

"Dahl was probably influenced as much by Disney as I was, and all of us have been, by the original Disney," Spielberg adds, referring to the earlier darker and edgier Disney works. From his own body of work, he offers E.T. the Extra-Terrestrial as a classic fairytale in that style.

"E.T. has darkness all the way through it," he says. "It's about divorce. E.T. almost dies and comes back to life. A fairytale isn't something that's extravagantly blissful. It's not. A fairytale really only works if it is truly and daringly dimensional. That means getting very close to the edge, getting very close to the abyss. The best fairytales do that."

In bringing The BFG to the screen, Spielberg is not using the book's iconic Quentin Blake illustrations,  even though those illustrations are to some Dahl enthusiasts as much a part of the narrative of The BFG as Dahl's own words.

"I said, I'm going to do the best job I can to equip the genius of Dahl, but I'm going to bring my own sensibilities in picturing the BFG the way I dreamt of it," he says. "The scale is different. Sophie is not as small in the movie as she is in the book. In the book she's a matchbox toy.

"In the film, she might be able to ride in the palm of his hand but he can feel her weight in the palm of his hand.  I wanted the scale to be bigger because I didn't think the audience could relate to a real relationship unless Sophie were a little larger in scale than the Sophie depicted in the book."

The book was first published in 1982, but Spielberg didn't come across it until 1988, when he read it to his then three-year-od son Max.

"He didn't understand it at three, but I read it to him three years later, in like 1991, and that's when he really understood it," Spielberg says. "And it really moved him. When he started to read on his own it was one of the earlier books he read. I've read The BFG to almost all my kids."

So, does Spielberg's work as a filmmaker take influence from his reactions as a father reading stories to his own children? "Probably. I first read The BFG out loud, because I never read it to myself first, [and] I should have," he says. "Luckily most of it, about eating children, went right over my three-year-old's head."

Director Steven Spielberg with Ruby Barnhill on the set of The BFG. Photo: Doane Gregory

Spielberg's job description is very simple: "I dream for a living," he offers. "That is what I do. Everything else, all the pragmatism that orbits my essential core dream, which is to be a storyteller, really doesn't have any impact on what I do; it just doesn't."

That said, he is surrounded by a multimillion-dollar production machine that churns out films that yield, in some cases, billions of dollars. "It's there and I can dip into it because I have a company which I run," he says. "We supply the hungry machine and I sometimes have to be a businessman."

Spielberg maintains that those universes – the show and the business – are separate worlds, and never the twain shall meet. "One doesn't effect the other, at least [in] the way I think about what I do," he says. "All the noise of the superstructure of the industry ... I know it's essential, but when it comes time to make a movie that all goes away, as if there's nothing out there."

Perhaps the most powerful demonstration of the enduring power of not only Spielberg's work, but of great storytelling in general, is that his best earlier works, such as E.T., stand the test of time, even in an era of cinema powered by digital effects.

"Fortunately, when a story is required to become an eternal story for all the ages is never up to me," Spielberg says, smiling. "That's the kismet. That's the sweet kiss of good fortune and good timing that has taken some of my movies and given them a longer lifespan, a longer afterlife.

"I never, ever design them to have that afterlife. I would never have been presumptuous enough to the point that I could determine, before I made the movie, that this was going to be one for the ages. Never. Not a single film that became, let's say, famous did I ever intend to be famous."

He thought Jaws would be "the tombstone that they were going to bury me under. I just barely got through that experience with my sanity intact. Then, for the film to go off and do what it did and to continue to reverberate even to this day, still makes me shake my head in kind of a amazed amusement or amused amazement.

"You can certainly hope for a lot if you have a big hit and you go off and make a sequel. Then the town will chastise you if it falls 20 per cent below their expectations. You might have made a one-billion-dollar film hit, but since it didn't make a billion five, you're a loser."

He says, the key to survival is to never look at the horizon when you're in the trenches making a film. "I never look at the horizon," he says. "The film may have the shelf life of a fruit fly or the film may outlive all of us. It's not up to me. I just tell the best story I know how to tell."

The alchemy lies somewhere between story, character, actor and moment. Though the precise measures of each is as elusive as a shadow on the wall.

"Usually with movies I'll work with character, the story will come from the character," he says. "Where Indiana Jones is concerned, it's the story first, it's the adventure he's on, it's the McGuffin​ of what he's after that has the ability to show us a different side of Indiana Jones, but isn't necessarily the reason I'm going to tell that story."

And yet some of the most memorable moments – the boulder chase scene from Raiders of the Lost Ark springs to mind – are pure moment, drawing from neither character nor story. That, says Spielberg, is where the actor takes centre stage.

"With a different character being chased by that same boulder? If it wasn't Harrison Ford?" Spielberg asks. "Harrison Ford is the only person that can get chased by a huge rock and show you an expression on his face that makes you feel that, in that moment of utter terror, we are him. He can be a hero when he lands but, when he's running for his life, he's all of us."

The BFG is released June 30.