It’s 1949. A thousand feet above the sea, three men tend Australia’s southernmost lighthouse, protecting ships from the Black Witch Rocks. Every day, they must check the workings of the lamp, which are ‘like a grandfather clock’, to assure absolute precision – or the light won’t reach the sea, and people could die.

This clip is an extract from The Lighthouse Keeper, a film produced by the Department of Information about the life of three lighthouse keepers and their families on lonely Maatsuyker Island, off the south-west coast of Tasmania. A Hitchcock-worthy soundtrack intensifies the drama inherent in both the men’s work and the landscape, with shots of waves eating at the black rocks and close-ups of the men cleaning the lamp’s glass prisms.

It was an era that presented documentary materials with the grandeur of a feature film.