Magnum Photo Gallery

Magnum Photos, founded by four photographers including Henri Cartier Bresson and Robert Capa following the Second World War, is the world's most famous photography agency.

But there has been a steep decline in the demand for agency photography from the press. Photo journalists have become more dependent on selling their work privately.

So how has the artform has changed in the world of the internet and digital technologies?

Some of the images on show