Born in Berlin on April 4, 1940, Ruetz studied Sinology, Japanese Studies and Journalism in Freiburg, Munich and Berlin, before turning to photojournalism. He was a member of the STERN editorial staff from 1969 to 1973. From 1996 to 2007, he was a Professor of Communication Design at the Braunschweig University of Art (HBK). His work has appeared in numerous exhibitions and over 40 publications.
