Before the Leica, cameras were cumbersome contraptions that involved hauling tripods that held the device steady during long exposure times and replacing plates over and over again. Not to mention, draping the requisite black cloth over one's head to focus on the image. But Oskar Barnack changed that.

Barnack, an engineer and precision mechanic at an optical institute in Wetzlar, Germany, invented the first, fully functional prototype of a still picture camera in 1914. This small piece, with a full metal body and collapsible lens, was called the Ur-Leica. Barnack was an avid photographer himself, but his asthmatic health prevented him using the heavy and awkward cameras of his time, driving him to tinker with the medium.

The Ur Leica and Leica cameras introduced the 35 mm film strip to still photography. High quality pictures could be produced by exposing a small area of film to create a negative, and then enlarging the image in a darkroom. World War I put a stop to all manufacturing activities in its immediate advent. But a decade later, Ernst Leitz II, who owned the optical institute, took a gamble and produced a 1,000 of these small cameras. Ironed out of all kinks, the improved Leica I was introduced at the Leipzig Spring Fair in 1925.

Today, the iconic Leica - a combination of Leitz and camera - has become synonymous with immortalising significant moments in history. One of the best known photographs is V-J Day in Times Square shot with a Leica by Alfred Eisenstaedt. The image of an exuberant American sailor kissing a nurse in New York City on 14 August 1945, as the Second World War came to an end, is a vital piece of photographic history.

But no photographer is more associated with the Leica than Henri Cartier-Bresson, who taught the world about the decisive moment in photography. He captured candid moments from ordinary street life, usually with a Leica 35 mm rangefinder camera fitted with a 50 mm lens. The unobtrusive camera, which he called an optical extension of the eye, gave him the anonymity he needed to blend into his surroundings and photograph his subjects in their natural element.