At first glance, the photography looks as ordinary as it can be. One elderly woman hobbles along a pavement on a walking stick. Another clutches her bag anxiously, as a a third strides towards her. A younger woman swivels round to stare at something. The fading figures on the mural, perhaps? The Japanese man walking behind her? Or, maybe she is struck by the bearded figure giving directions to yet another stick-toting old lady - except that this one's a nun.
On closer inspection, the image is anything but ordinary. Look at the body language of the people on the pavement: how old old lady's foot appears to be squashed by another's, and how the Japanese man doesn't seem to notice the bearded guy's hand clipping his ear? Gradually, it becomes apparent that they can't all have been there at once. Think about their eyes - the way they evade contact, even when looking straight at each other - and you wonder whether any of these people were there together. There's even something unsettling about the street sign - it's face turned stubbornly towards the mural, so no-one can see it.
The reason the image looks 'off' is because it is. Like all the photographs in David Weightman's Ordinary series, the scene was constructed by cutting and pasting shots of people walking along the same stretch of pavement at different times. 'Originally the project was to do with time and repetition, but as it progressed, it became clear it was more about a desire to make things happen,' explains Weightman, who produced Ordinary for his degree show at the Surrey Institute. 'By putting people together in a scene who weren't there at the same moment, I created relationships and tensions between them.'
All the photographs in the series were taken in the winter and spring of 1999 in Surrey towns, such as Farnham and Aldershot, near Weightman's family home in Cobham. Citing his influences as street photographer, Phillip-Lorca diCorcia, as well as L.S. Lowry and Gustave Cailebotte, both painters obsessed with depicting working class life, Weightman set out to photograph 'ordinary people doing ordinary things'. The litter-strewn streets, shabby council estates and kebab joints he chose as backdrops look more like depressed parts of Tyneside than the stereotypical Surrey stockbroker belt. The same ambiguity is reflected in his timing. Weightman shot most of the images on 'weekends or Wednesday afternoons, times when you don't expect anything to happen', and only photographed 'on overcast days, so I could work from a blank canvas.'
Weightman does not know any of his subjects, and makes no attempt to analyse their sociology. By re-engineering the timing of their movements, he plucks them out of context and turns them into the unwitting actors in a drama of his own devising. 'Once the location is sorted and the weather's okay, I set up the camera on a tripod and photograph the same location, sometimes for a few hours', he says. 'Then I select a number of images from all the ones I've taken, scan the negatives and cut and paste them in Photoshop (a software programme).'
The longest part of the process is selecting the images. 'I spend hours looking at contact sheets and putting one image with another to see how they work, because there are always several different possibilities,' explains Weightman. Some of the dozen photographs in the series, like the mural scene, are cluttered with people. Others are sparser, such as the shot of a frail old man who seems to be standing alone on a windswept bridge until you glimpse a hand creeping around the corner. 'That's one of the subtlest images.' says Weightman. 'It works as well as the others but on a different tangent. It's all part of the process. How to tread the line between probability and improbability without giving too much away.'
Alice Rawsthorn is director of the Design Museum, London.