The Sundance Directors Lab, which took place this month at the Sundance resort in the Utah mountains, has opened its doors to a new wave of international film-makers. Mike Goodridge visited the lab and met some of the writer-directors being put through their paces.

A fair amount of legend has built up around the Sundance Institute's Directors Lab, which takes place in the Utah mountains over three weeks in the summer. This, after all, is the workshop, or as one of this year's participants Adewale Akinnouye-Agbaje describes it 'boot camp', which has seen some of the most exciting film-makers of the last three decades pass through its process before they made their first films. The list is astonishing. Quentin Tarantino, Paul Thomas Anderson, Gregory Nava, Kimblery Peirce, Nicole Holofcencer, Hany Abu-Assad, Miranda July, John Cameron Mitchell and Tamara Jenkins are just a few.

A visit to the lab dispels many myths about the mysterious alchemy that occurs there. Although it takes place in the bucolic Sundance Resort nestled in a canyon underneath Mount Timpanagos, the 100 or so people who have come from various parts of the country and the world to take part have little downtime to soak up the sun. Six days a week for the four weeks of the lab (May 28 to June 23), the eight film-makers ('fellows') and their teams work at full intensity from the crack of dawn to 8pm. Every night an advisor screens one of his or her films or one of the scripts is given a reading by the company of actors to the entire community. If they're lucky, people can grab last orders at the mountain's popular Owl Bar as a way of winding down before collapsing from fatigue.

So what exactly goes on during the day' The eight directors who have been selected for the labs choose between four and eight of the most challenging scenes from their scripts (which, in this year's case, they have all written themselves and seven of which have been through the screenwriters lab) and shoot them using professional actors and crews. After a week of preparation and workshops, they have 18 days in total, made up of four different rounds of rehearsing, shooting and editing. Once a scene is cut by one of the four professional editors on site, the footage is screened to the group of top advisors enlisted to come to the mountain who then sit down with the film-makers to offer feedback. Advisors at the labs this summer included Atom Egoyan, Catherine Hardwicke, Brad Silberling, Peter Medak, Jon Amiel, Fernando Leon de Aranoa, Doug McGrath, Sandra Nettelback and, when he was available for days off from post on his latest film Lions For Lambs, the grandfather of the whole programme, Robert Redford.

The whole notion of the Labs is not to show the footage outside the labs or deliver an assembly. As the Institute's well-known Michelle Satter, director of the feature film programme, explains, the labs aren't about results, but process.

'The pressure here is for them to take risk and push the boundaries of their work,' says Satter, who has been working on the labs since Redford started them in 1981. 'The fellows are here to learn the tools, to work with actors, use cameras and work with editors. They are encouraged to choose scenes by which they are most challenged, the scenes which keep them up at night. We want each scene to present a different creative issue for them to be explored. It's a dress rehearsal for their project.'

The facilities at the lab are of a predictably high standard. The rehearsal hall is subdivided into three sound stages, the resort screening room hosts screenings of scenes and script readings. Two long trailers are brought in to accommodate eight edit rooms, a large tent is constructed for breakfast, lunch and dinner and a yurt for the lab administrative offices. Otherwise, the productions use the natural landscape for location shooting or houses on the mountain, lent to the Institute by homeowners. 'We've shot everything here,' says Satter. 'The New York subway, South Bronx, Vietnam, Africa. Obviously the sets are rudimentary but the focus here is on the dynamics of the scene and ensuring that the scene works.'

In 2003, the Institute began an initiative to include international projects in the summer labs and Alesia Weston, the feature film programme's associate director who specializes in international explains that, of the 13 projects (eight in the directors lab, an additional five in the screenwriters lab that immediately follows), four or five are now international. The initiative has already paid off. In 2004, two of the fellows were Palestinian Hany Abu-Assad and his project Paradise Now, which went on to win a Golden Globe and an Oscar nomination, and Israeli Dror Shaul with his project Sweet Mud, which went on to win the world dramatic jury prize at the Sundance Film Festival this year. At the 2005 Jan Screenwriters Lab, one of the selected projects was The Advance Party by the UK's Andrea Arnold, which would become Red Road. New Zealander Taika Waititi's Something Beginning With Love, which would become Eagle Vs Shark, was a summer 2005 lab alumnus.

'Sundance doesn't impose a US narrative style,' says Weston, who also oversees the Sundance/NHK award programme and sister labs in other countries, like the Middle East Screenwriters Lab in Jordan. 'Most of our advisors will fight to preserve the director's voice.'

At this year's Director's Lab, one of the most talked-about projects on the mountain is Farming, from Nigerian-born Englishman Adewale Akinnuoye-Agbaje (aka 'Wally'), who is moving to directing after a successful career in acting in films like The Mummy Returns and The Bourne Identity and recurring roles in TV series Oz and Lost.

Farming is an autobiographical screenplay by Akinnuoye-Agbaje expanded from a self-financed short which follows his early life when his parents came from Nigeria to England in the 1960s and 'farmed' him off to a working-class white foster family in the small docking town of Tilbury in the southeast. Akinnuoye-Agbaje grew up the victim of relentless racist violence and eventually, paradoxically, found a haven of sorts as a member of a skinhead gang. The script, which culminates in a reunion between the boy and his mother, has already been getting interest from producers and financiers on both sides of the Atlantic.

Akinnuoye-Agbaje is shooting a complicated scene, in which the boy is being goaded into a fight at school with a new Asian student, when I meet him. 20 extras have come in from a local Utah high school to take part and by the end of the day, he has shot 42 set-ups, 'a record for the Labs,' he brags.

'Directing is no joke,' he laughs. 'My reason for coming here is to experiment with what I don't know. I have a concrete idea of what I want and I wanted to come here and try some of the shots I wouldn't ever dream of shooting on my own. Logistically you learn how to block, but on a personal level you learn about your own personality, the strengths and weaknesses that you have to learn as a director. For example, this is the first time that I've learned that the DP is here to help me materialize my vision. I don't have to know everything. I can't know everything.'

Annette Davey, an Australian-born editor who works in the US and has credits including Waitress, The Sleepy Time Gal and Sorry, Haters, is not so amused with the 42 set-ups which Wally brings her to cut the next day. Davey is assigned to two fellows - Akinnuoye-Agbaje and Eric Lahey, who is here with his own autobiographical project Spoons - and has an incredibly tight deadline of 6pm that day to craft the completed scene. Starting at 7.30am, she and Wally work quickly together, and all the while she is pointing out what coverage he has missed which would have been useful and constantly reminding him of the emotional core of the scene and how each image can be used to back that up.

Another of the directors Sophie Barthes is working next door with her editor Jonathan Alberts (Wristcutters) on scenes she shot the day before for her project Cold Souls. Barthes, a Frenchwoman who has lived in New York for seven years, is further ahead on her project than most of the other fellows. Paul Giamatti has signed to star and produce with his company Touchy Feely Films and shooting is set to start in Nov. Giamatti only got involved recently, but Barthes always wanted him to play the lead character - an actor called Paul Gianelli - who stumbles on a private lab offering New Yorkers a relief from the burden of their souls. But once his soul is extracted, his life is thrown into turmoil.

David Eigenberg, who played the key role of 'Steve' in six seasons of Sex And The City, is playing Paul for the purposes of the lab. 'Dealing with actors is my main focus here,' explains Barthes. 'I think my principal weakness is not understanding them but that's a tool you can refine with a lot of practice.'

She says she chose the scenes with most dialogue to shoot here. 'You can see on screen if it works or not, or if you should trim it to help the comic timing,' she says. 'I also have a strong French accent and have that accent in my head as well, so it's good to hear it spoken with American accents.'

I sit in with Barthes over lunch with one of the advisors - celebrated editor Andrew Mondshein (The Sixth Sense, Desperately Seeking Susan, The Cider House Rules). Mondshein tells her that there is no rule for shooting comedy and that she should experiment at the lab with handheld, static and fluid styles. Having also read the script, he points out concerns he has with the third act and omissions of narrative in the soul-extraction process.

'You have to be open like a sponge to take in the suggestions, but at the same time you have to be a little but stubborn and maintain a strong idea of your script,' she says. 'The advisors don't push you. They tell you to take away only what resonates with you. But if six people tell you you have a problem, you realise that you have a problem.'

Veteran Hungarian film-maker Gyula Gazdag is artistic director of the lab for the 11th time and his role is to liaise between the projects and the advisors and ensure that all is going smoothly. 'Because of the nature of the lab, there are crises every five minutes,' he says. 'I need to decide if they are crises which harm the project or which help the film-maker to learn something. For example this morning, six local actors were coming up to be in scenes and they had a flat tire. Then one of the DPs got sick. Sometimes the director doesn't get along with an actor and I have to work out whether it's something that's going on with the actor or whether the director doesn't know how to talk to the actor.'

He stresses that the advisors are as enriched by the process as the fellows. 'They often say that the lab returns them to their first and most important motivations for why they are doing this,' he says.

Keith Gordon would agree. The actor and director of Waking The Dead, A Midnight Clear and The Singing Detective has been coming to the lab for eight years. 'Being an independent film-maker these days is more like being a professional fundraiser,' he says, 'so it's artistic heaven here. Being part of the creative film-making process here and watching the young film-makers learning from other advisors is an inspiration.'

Gordon explains that all the advisors meet first thing in the morning when Gazdag and Satter give an overview of each of the projects and the advisors share information on the projects to which they have been assigned. Then they each move on to different projects, usually kicking off with lunch with a new fellow.

'Some need a heavier hand, some a lighter hand,' he says. 'Stanley Tucci, for example, is very good at being direct like a good strong father figure. I'm more of a mother.' Gordon had been on set of a scene from Cold Souls the day before and advised Berthes to shoot a couple more shots than she was planning. 'She wanted to shoot the whole scene in one shot. She ended up doing what I had suggested. But we give them points of view, not orders.'

As for Robert Redford, Satter explains that he is 'kind and compassionate, direct and honest' with the fellows. 'Once people relax with him, he is an extraordinary advisor.'

It's award-winning Spanish director Fernando Leon de Aranoa's first time as an advisor and he says it's an intense experience. 'I feel like I do when I'm shooting a film,' he smiles. 'We work 12 to 14 hours a day starting very early in the morning.' He says that, for all the fact that the fellows have no financial responsibilities here, they are still working under the greatest pressure of all - time. 'All the pressures of money in shooting is translated into time,' he says. 'It's about an actor's availability or limited time to shoot at a particular location. They have those same pressures here.'

Indeed, Satter admits that, although the raison d'etre of the lab is to provide a safe creative place away from the financial hassle of getting a film made, real world issues do come up. 'It's about learning how to communicate and deal with your panic,' she says. 'Directors are used to working on their own, so they have to learn to be open. If you stay in defensive mode here, you are wasting the experience.' She also adds that the feature film programme staff take great efforts to assist fellows with follow-up, be it feedback on new drafts, or help with finding money, producers and casting. 'We have a pretty good track record,' she says. 'Each individual project has its individual journey, but about 50% of the lab projects end up getting made.'

'You're in love with each other, but there's no fucking,' smiles veteran actor Jamey Sheridan (The Ice Storm, Syriana), who is working with Eric Lahey on Spoons. 'More than half the people arrive with a chip on their shoulder but lose it when they come here. Everyone is in the same place - actors and crew. There are no stars. It's about as flattened out as I've ever seen. You've got nothing to lose here.'