"He (Wang) is a slow photographer," Xie says. "He thinks a lot about what angle he will shoot from and how to take advantage of the environment to serve his aims. He goes through all the detail, intent on letting everything in the picture tell its own story."

Xie, on the contrary, describes himself as sometimes tetchy, something that may partly come from his preoccupation with basic rural education.

He was a bench worker before formally beginning to learn photography in 1978, wishing to record his son growing up.

In 1987, when his home was full of awards he had won through warm, feel-good pictures, he started to rethink what he was doing as his photography teacher encouraged him to take pictures that would make those who viewed them think rather than to make them happy.

In the countryside of Guangxi Zhuang autonomous region that year he took a photo of a teacher, 29, giving a class with her 5-month-old daughter on her back.