Catherine Yass/ The Human Cannon Ball

Catherine Yass's photographs taken out of a lift are well known. The blurred buildings, zooming past the camera, are also an image of falling - our falling.

This still from Yass's film 'High Wire' depicts a funambulist, a high wire walker. High wire walking is the last circus discipline left where performers still risk life and limb with no safety net, so we don't have to. The funambulist here is Didier Pasquette, one of the very few left in the world. During filming, he had to turn back after a few steps. Apparently it was too windy, but no explanation is given in the film or notes. Strangely, way this work encompasses failure as much as audacity.

I saw the human cannon ball perform his act at the Cornwall Show last year. Four counties clubbed together to bring him over from the States. I was very touched by his act. There is something strangely life-affirming about someone who will get himself shot 80 feet up, until he becomes literally a dot in the air - a truly pointless and heroic act.

I like the multi-exposure element of the photograph - it reminds me of Muybridge's horse shots - but it doesn't sufficiently convey the outrageousness and loneliness of the endeavour. Yass's image shows that element much better.