Abstract photography - a genre developed in the early twentieth century by an international avantgarde of artists such as Man Ray, Laszlo Moholy-Nagy, Paul Strand and Alwin Langdon Coburn - has until now been little acknowledged as a type of imagery and art in its own right. It is rather the opposite of realistic reproductive photography and comprises photo work that does not focus on the tangible object. A distinctive part of the fine arts, it has its own specific subjects, forms and functions. The artistic and scientific frame of this book is based on the lectures and discussions held during the 21st Bielefeld Symposium on Photography and the Media under the auspices of the Fachhochschule Bielefeld. The meeting was explicitly aimed at raising public awareness of the art of abstract photography. It was not concerned with the photo as a medium, with questions on the subject and the technique of its visualisation, but instead with what it visually is : the visibility of an impending age .