It may be called the Politics Of The Image but the most effective work in Alfredo Jaar's new exhibition is one that is largely without images.

The Sound Of Silence is an eight-minute film that tells a brief story about the provenance of a famous press photograph. Taken by Kevin Carter in the early 1990s during the Sudanese famine, it shows a little girl too exhausted to move. She lies collapsed while just a few feet away a vulture awaits its chance.

In spare language, we are given facts on Carter's troubled life and the events that led to him taking his Pulitzer Prize-winning image. The words appear in a typewriter font on a black screen and the photographer's name is repeated like a poetic refrain.

With a flash of bulbs, we are finally shown the photo. It's an image that provoked worldwide condemnation, since Carter did not attempt to help the girl.

Just a year later, he took his own life. It's powerful film in which minimal words create all the images we need for a potent, painful tale.

By contrast, Jaar's second film, Muxima, with scenes of life in Angola, has a lively soundtrack. Divided into 'cantos', it makes a nod to poetic form, but is too desultory to have much impact.

Until Apr 6, South London Gallery, 65 Peckham Road SE5, Tue to Sun noon to 6pm, free. Tel: 020 7703 6120. Rail: Peckham Rye