Ercilia Mamani Quisbert

Mamani Quisbert grew up in Llallagua, where her mother sold pig-fat candles to the drilling crews. From 1991 she ran a portrait table at the pithead of a mining cooperative above the town, making identity photographs at forty bolivianos each: four thousand faces in eleven years, every one posed in the time it takes a man to lift off his helmet. She can settle a stranger's shoulders in twenty seconds and does not talk while she works. When she changed to wet plate in 2003 she kept the table, the stool and the two-metre distance.

She pours collodion in a plywood darkbox towed behind a bicycle. At four thousand metres the ether flashes off fast, so the mix is cut with extra alcohol and the plate must reach the silver bath inside a minute and the camera inside two, the bath riding wrapped in a wet wool blanket to hold twelve degrees. One whole winter came up veiled in grey: tailings dust in the silver, which no eye can see in a tin tray. She filters through cotton wool now and re-suns the bath on a bus roof in La Ceja.

There are three hundred and eleven plates, each on blackened aluminium, each unique, and she makes no prints from them at all. She works at the pithead in daylight and refuses to go underground, since the men have enough dark without her adding a camera to it. She will not photograph anyone whose name she cannot spell, and she writes that name on the back in grease pencil with the date and the direction of the wind.