Oscar-winning documentarian Kevin Macdonald has his work cut out for him with his latest project. Life in a Day is an experiment that blends the immediacy of home filmmaking given a global platform on YouTube with a curious anthropological look at life in the digital age.

This coming Saturday, 24th July, Macdonald and producer Ridley Scott have asked anyone with a camcorder to film a day in their lives and submit it for inclusion in the project. He'll then blend the clips together to create a feature film, which will premiere at next year's Sundance Film Festival. 20 of those whose contributions make the final film will be flown out to Park City, Utah to attend the premiere.

But what does he expect to receive? How will he sort the footage? Will he be inundated with amateur porn? Sitting down with Cinematical for his only interview ahead of the big shoot day, Macdonald reveals all about his hopes and fears for the project and explains how you can take part.
Do you have any idea what you're letting yourself in for? Do you have a picture of the sort of footage you might expect to receive?

Well, to an extent, but I don't want to prejudice people who might read this, or myself really, by saying what I'm expecting to receive.

I think there'll be at least two or three structural elements to the film. One will be a temporal one; there will be some sort of chronology, starting at dawn and ending at night. Another will be musical. I'm working with Matthew Herbert, who's a very interesting avant-garde composer who uses found sounds to create a score. So people will also have the opportunity to record sounds, which he will then use in the film.

The third level of structure is the thematic one, and honestly I don't know what the themes and preoccupations of people are going to be. What are people going to film? Am I going to get 10,000 people brushing their teeth or taking their dog for a walk? In some ways that could be amazing – 10,000 people taking their dog for a walk, cutting from one to the other to the other, seeing the different environments they're in and the different dogs, that could tell you a huge amount about life today and be very entertaining.

Or it could be that I get a lot of people who are intimate or confessional and actually tell me things; maybe their love life is going wrong. There could be a whole film in that, possibly. I don't know what kinds of things people are going to come up with, all I've really asked is that they film something on that day.

I've also asked them to answer a few questions as a secondary thing – what they love the most, what they fear the most, and what they've got in their pockets. I want to try and get them into the right frame of mind to be intimate and confessional and honest. That's the important thing – the intimacy and honesty.

But it's all an experiment; we could all fall on our asses! We have no idea how we're going to put it all together. The editor is waking up with nightmares every time he thinks there could be even more footage than we first thought coming in.

Are you conscious of the fact that a lot of people might be performing as opposed to being themselves?

I'd rather people didn't perform, but the presence of a camera inevitably leads most people to perform to one degree or another. You could say that people who are going to be good are the better actors, but I'd rather say that they're more being themselves.

People can use it as an opportunity to voice their concerns about the world or local or national politics and so I think there'll be a strong political element to it. But I'm hoping – without getting too We Are The World about it – it'll be life-affirming, and generally revelatory about the preoccupations of people. I think the preoccupations of people are probably very different from what we think they are.

There will be an inherent bias in the sense that it will only feature work from the sort of people willing to put themselves forward in such an exhibitionist sort of way – do you counter that or do you explore that as part of the narrative?

Well one of the things we've done to level the playing field somewhat is that we've sent out 500 cameras out to the developing world, in the five corners of the globe, where they don't have the Internet and don't have cameras. In doing that we're trying to get perspectives that aren't all Yale law students in the dorm and media-savvy 20-something Londoners – although they may well produce the best stuff, I don't want to stop them! I think the point is that it has to be in some way representative of the world.

Yes, it's always going to be self-selecting. I'm sure we'll get few people in their 70s and 80s taking part – though I hope we get lots – so, yes, there is a bias to it. But of course the conceit is fallible – there's no way we're going to be able to represent the whole world, and there's no way we're even going to be able to represent this segment of the world when we cut it down into a feature-length film. But the conceit is still there and still stands.

What do you think the democratisation of filmmaking means for cinema?

I'm sure you've seen Eleanor Coppola's documentary on the making of Apocalypse Now. It was made in the 90s, and at the end Francis Ford Coppola is interviewed in the then-present day. He's sitting there with his vineyard behind him, and he starts talking about the experience and what it was like to make Apocalypse Now. He says, "Well, of course filmmaking is changing because of these little cameras that are out there that cost very little money that everyone has, there's equality of opportunity in filmmaking that didn't exist when I was making films. And right now there's some fat little girl in Idaho who's the new Mozart of cinema using her mother's camcorder to create a new grammar and language of film."

At the time that was a really fascinating observation. Of course it hasn't come to pass. That's the interesting thing. You can make a film now for nothing, effectively. If you've got a laptop and a camera you can make a film to a professional standard. And yet not a lot of people have done it. There are a lot of bad films being made, but the new Mozart hasn't come out. And it's very interesting why that is.

What we're trying to do with this film is to marry what's unique and extraordinary about user-generated content, with a professional and experienced filmmaking team, and hope that we can actually harvest that material. There's so much out there and so many people who want to capture parts of their lives on camera and turn it into footage that really works.

You have a very specific deadline, too...

Yeah, we're going to show the film at Sundance and the best 20 entries as judged by Ridley Scott and myself, those people will be asked to come to Sundance for the screening and we're hoping to do it as a life musical event where Matthew will create the music live.

Are you going to be shooting any footage?

I'm going to shoot something, yeah. It might end up in the film - if I'm judged to be good enough! There may be a bit of bias! No, I will shoot something, but it may not be any good - that's the thing about all documentaries is that there's always a risk that you film and you think what you film is going to be interesting, but actually it's dull because you're not controlling it.

The day to shoot your segment for Life in a Day is this coming Saturday, July 24th. For guidelines and further information, head over to the YouTube page.