Colourful new discoveries from the early days of photography, 1980

‘Extra-long exposure times – 30 times longer than black and white – meant discomfort was an inevitable part of the process’: the work of the Lumières reassessed, 1980. Photograph: Paul Bergon

A nude woman reclines on a tumble of fabric, a flower in her hair and bracelet on her wrist, frankly challenging the viewer with her gaze. It’s almost Manet’s Olympia, but not quite. This photograph is an Autochrome, the process invented by Auguste and Louis Lumière in 1904 and explored by the Observer Magazine on 2 November 1980, with recently unearthed images from the French Photographic Society.

The secret to Autochrome was an unlikely ingredient: potato starch