In the 1990s, Wolfgang Tillmans made a name for himself with photos of parties and club life. Today he is one of the most famous photographers in the world. Filmmaker Heiko Kalmbach accompanied Tillmans for four years. The result is a personal portrait featuring impromptu interviews and documentation of the immediate experience of Tillmans' work process. 'If One Thing Matters - a film about Wolfgang Tillmans' is a search for the core of an influential artist's practice.