Bas Princen (1975) and Stefano Graziani (1971) are known for their photographic work but are both deeply involved in architecture. In this discussion with Kersten Geers, they try to shed light on Lewis Baltz's work and link it with architecture and, more specifiaclly, metropolitan architecture. The discussion took place at the EPFL (École Polytechnique Fédérale de Lausanne), at the ''Project Room'', on the 15th of December 2015 and is part of the Fall Semester program of FORM, '' Paris-Tokyo: Metropolis''.