Right. You have a single reel of super 8 film, giving you three minutes and 20 seconds to tell your story.

There’s no editing, and you must film the scenes in the order in which they happen, no matter how difficult that is to do. Oh, and you’re making a silent movie – if you want a soundtrack or a voiceover you’ll need to add that on afterwards. If it works, your efforts could get shown at Cannes. But if you make a mistake? Well, there’s always next year.

The Straight 8 competition, now in its tenth year, invites film-makers from all over the world to spend an unpaid weekend making a three-minute film. The prize is the chance to see your movie shown in the Curzon Mayfair, on Channel 4 and at the Cannes film festival. The only catch is those rules.

“It’s beyond guerrilla film-making,” says Patrick Craig, in real life a producer of ads and music videos. Almost all of the contestants are employed in the film industry, many doing slick, big-budget commercials in comfortable Soho production houses. So why would they want to leave that luxury and start making a film on super 8? “I get tonnes of e-mails saying, ‘I learnt more doing this than any other experience I’ve ever had in film’,” says Ed Sayers, the competition’s founder. “The things that make it difficult, like the deadlines and the constraints, seem paradoxically to be the things which make people actually get on with making a film instead of just sitting around talking about it.”

There’s a treasure-hunt atmosphere as participants race to make their films. Last year the London cinematographer Suzie Lavelle stepped in on the morning of shooting to replace a director of photography who was taken ill – she had to use an almost defunct camera, but the result was Sticks and Balls, a saucy golf-themed music video, which has received thousands of hits on YouTube (you can watch it on the Straight 8 home page).

Few are counting on this to be their big break – most seem to be taking part for the enjoyment. “Contestants send the films back to us for processing, so they don’t get to see what they’ve done,” Sayers says. “There’s nothing like the adrenalin of knowing that the first time you’ll watch your film is the moment it’s shown on a screen in front of an audience.”

“Hearing the audience laughing is what I’m doing it for,” says Ben Fogg, whose impromptu effort, Beard, was given a cinema outing last year with 20 other winners. Beard featured a twenty-something shaving off a beard that he believes brought him romantic bad luck. This year, Fogg is putting in the hours on a film called Jog, about a would-be stand-up comedian who whiles away procrastinating hours with a new fitness regimen.

In Ali’s Café in Stamford Hill, northeast London, where they are filming on Passover, the producer Alice Astley gazes out at a parade of Hasidic clowns and children dressed up as policemen. The director of photography is balancing the camera on a contraption built of a skateboard and a broomstick. “And that’s not even the best device we’ve used during this film,” they say. Earlier they got a shot of a man running by driving alongside him, resting the camera on a piece of foam to stop it bumping on the car door.

“It’s quite hard to do well,” Astley says later. “But equally, it feels like you can be quite maverick about it, with a hit-and-run spirit, because you can’t spend hours poring over an edit suite trying to finesse the film into something it isn’t. You have to give up your usual high standards, put the cassette and soundtrack in the post, cross your fingers and hope for the best.”

With entries from Mexico, Canada, Spain and Scandinavia, Straight 8 gets bigger every year – this year there were almost 200 entries. Sayers is planning his glitzy media screenings in London and Cannes, but he’s also anticipating showings at independent cinemas around the country. “I want to show as many of the film-makers’ works as we can, because it’s the greatest feeling to see your own work in a cinema. It’s the fastest – and slowest – three minutes of your life.”

Rushes Soho Shorts Festival, until August 1, is showing 75 of the best Straight 8 films over three nights at the Curzon Mayfair, July 28 and 29, 8.45pm; and the Renoir, July 30, 8.45pm (both cinemas in Central London). www.straight8.net

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