Thomas Kellner is a German photographer known for his large-format photo mosaics of architectural monuments created using contact sheets and varying perspectives. He studied art, sociology, politics and economics at the University of Siegen. In 1996 he received the Kodak Young Talent Award, which encouraged him to live as an artist. He lives and works in Seigen. Rolf Sachsse is a trained photographer who studied art history, communication studies, and German literature at the universities of Munich and Bonn. After finishing his PhD. on the relation between architecture and photography in the 20th century, he worked as a curator, writer, and photographer. He was Professor of Design History and Design Theory at the University of Fine Arts Saar, Sarrebruck, where he also was Pro-Rector of Academic Affairs until 2017. Since 2018 he has been a lecturer at the University of Bonn.