Behind the Gare Saint-Lazare

A man leaps across a flooded lot behind a Paris railway station, his heel a split second from shattering the mirror of water beneath him. Cartier-Bresson shot it through a gap in a fence with his screw-mount Leica — he could barely see; instinct timed the frame.

No photograph is more identified with the idea that a small, fast, quiet camera lets you catch the exact instant when geometry and life align. It became the manifesto image for "the decisive moment" — and for the Leica as the instrument of it. The print is copyrighted (Fondation HCB/Magnum), so we link to it rather than reproduce it.