Kaufmann’s Posographe: An Amazing Exposure Calculator from the 1920s

Kaufmann’s Posographe is an intricate pocket-sized mechanical calculator invented back in the 1920s. Measuring 13x8cm and filled with tiny scribblings, the device allowed photographers to approximate the exposure values they needed by simply sliding around six small pointers.

Technology has come quite a long way since then, eh?

Kaufmann’s wonderful Posographe [History of Computing]