When he used to live in Edinburgh more than a decade ago, Scott Graham didn't get to the film festival much.

He'd be too busy working in coffee shops or working on scripts. And when he wasn't, sometimes he just didn't have the money to go. "But I used to read the programme cover to cover," he tells me today. "Even the programme gave me an awareness of the stories that were being told from different parts of the world."

In this year's programme you'll find Graham's name on page five. He is the director of this year's festival closing night gala, Iona, a beautiful, bruised, bleak film about love and faith and regret that sets human damage up against the consolations of landscape. So he's probably going to go this year. He might even wear the kilt he bought to go to Cannes a few years back.

But that's a problem for the future. Right now he's sitting in his flat in Cathcart trying to write and getting his head around the idea that he has become what he always wanted to be: a film director. "I can't believe I've done two features," he says near the beginning of our conversation, the disbelief there to be heard in his voice.

But he has. His debut Shell, set in a petrol station in the Highlands, introduced us to the actor Chloe Pirrie who was recently seen in the BBC spy drama The Game and has since been filming a new version of War And Peace. And now Iona - the name of the title character played by Ruth Negga, as well as the film's location - sees him return to rural Scotland.

It's a story about a mother and a child fleeing the city to the place she grew up in and stirring up some deep, roiling emotional currents when she gets there. It's a dark story born out of sunlit memories.

"I went to the island when I was a kid on holiday when I was 10 years old with my mum and my sister, and the experience of being there never left me," Graham explains. "I remember the journey, the two boats; the big ferry and the smaller boat you catch from the other side of Mull. And I remember being picked up by a horse and cart. I don't remember there being any cars there. There were one or two cars belonging to the islanders themselves when we were there this time around but I don't remember there being any when I was a kid.

"I remember camping. I remember boiling potatoes in sea water. Some of these things even found their way into the script. I grew up in the north-east near Aberdeen. It wasn't as if I was from an urban environment, really. But I thought the island was very different to anything I had experienced."

This all sounds bucolic, doesn't it? And yet the film he has made is no comedy. It's a story of families divided. That was always the plan, it seems. "Before I made Shell I knew I was going to do another story about a conflict between a parent and a child and also a conflict with where they are, the landscape they find themselves in. Somehow that led me to a woman and a son returning to Iona."

But where does a film begin anyway, he asks? He remembers seeing Peter Weir's film Witness, in which Harrison Ford plays a cop hiding with an Amish family, while writing Shell and he wonders if that hasn't fed into the new one too.

What I want to know, I tell him, is given that his films plough the deep, loamy furrows of human sadness, can we attribute a philosophical position to him as a result. Does he, like Brecht, believe that "he who laughs last has not yet heard the bad news"?

"No, I definitely don't." He's laughing while he says it. Yes, his films are full of people who hold their tongues. But he's not sure that's a sensible strategy.

"I do think you can do quite a lot of harm to yourself and your loved ones if you bottle things up. You need to let it out. I hate to quote the Bible to you but there's a great line in the Bible: 'When I kept silent my bones wasted away.' This idea of holding onto something that you should let out can be quite destructive. I think I'm more concerned by the damage we do to ourselves and each other - the emotional damage. But I wouldn't say I'm too pessimistic."

He himself is not religious but he doesn't condemn those characters in his film who are. Not for their faith, anyway. "There are some weak and some flawed characters, particularly the male characters but I think that's because they're human beings."

Okay, I say, what about your use of landscape. Iona, like Shell, finds real beauty in rocks and sand and grass. Is the beauty of that landscape there as a solace or as a reproach to the characters for getting wrapped up in their own problems. "That's interesting. Almost being a rebuke for not paying attention."

He thinks about this. "I do think Iona has more of a direct conflict with this island than Shell does. Shell is lonely and there's an awareness of the isolation, but at times Iona almost seems to be fighting with the island or hiding from it. In some ways she is picking up where she left off as an angry teenager."

That's one of the reasons he thinks Ruth Negga is so good in the role. "With Ruth there's a toughness to her but it's also very easy to see her at times as a teenager."

You get the sense talking to him that the stories he told are not finished to him. Talking about Iona, sometimes it sounds as if he is still discovering his own film. As if he is as confused and uncertain about the choices made by his characters as they are.

"I do find myself sometimes watching it and thinking 'why there?' It's almost the worst place Iona could have gone. But that's where she goes."

Graham grew up an hour from the nearest cinema so his cinematic education came from the small screen, back in the days when television actually took cinema seriously. He fell in love with the form watching Alex Cox present Moviedrome on BBC Two back in the 1980s. "I saw Badlands, One Flew Over The Cuckoo's Nest, Five Easy Pieces and stuff like that. But I also saw a lot of European stuff and indie stuff that was coming out of Canada. It just helped me to look at what I was watching as more than just a movie, or as entertainment."

It should be said he does have a life outside film. He goes swimming every day, he says. He is married to the actor Morven Christie, though they're currently separated. And when he has time he'll go north, go home. "If I'm not writing I might as well be outside. And my mum's got a big messy bit of ground that always needs work. So I go up there and just do something useful."

Five years from now he hopes he'll have made another three films including one set in his home town of Fraserburgh loosely based on a Bruce Springsteen song. And, if he's lucky, he says, he'll have a garden of his own.

By the sounds of it that garden will be in Scotland. Ask him and he'll say that, yes, he sees himself as a Scottish filmmaker. "I do. I'm not entirely sure what that means yet. Scotland is evolving, isn't it? Someone asked me recently what it's like to be a Scottish filmmaker at the moment. 'Is it exciting?' And I said 'It is exciting to be Scottish full stop at the moment'. I feel it's all wrapped up with what is happening in Scotland at the moment and personally I feel quite optimistic and excited. But I'm not sure I know what a Scottish filmmaker is."

He could always take a look in the mirror.

Iona is the closing night gala of this year's Edinburgh International Film Festival on Sunday June 28, www,edfilmfest.org.uk