"Hein Gravenhorst's PHOTOMECHANICAL TRANSFORMATIONS have rested in oblivion for half a century. They are among the key works of Generative Photography, a movement of the 1960s that introduced the algorithmic program and a strictly methodical-serial conception of the image into the history of photography. It is an aesthetic program that gives preference to the form-giving qualities of photography over its depictive and representational ones. Within the history of this genre, the photomechanical transformations of Hein Gravenhorst are of central importance. Hein Gravenhorst is an exponent and main representative of this style. As one of the four artists of their first manifesto in early 1968 in Bielefeld, he is one of its founding fathers.
'PHOTOMECHANICAL TRANSFORMATIONS came into being under the aspect of programming aesthetic structures whose production can be formally described according to the insights of a superior, rational aesthetic and whose process is built up according to two principles,' is Gravenhorst's dry opening statement to his FOTOMECHANISCHE TRANSFORMATIONEN IN OUR LICHTREFLEX TRANSLATION - ROTATION, 1965. Taken only as constructs of their own making: 'You do not take a photo; you make it!'
This realization has become a trend, a 'turn', and has led to a cultivation and artistic appropriation of precisely this transformation process. And not only figuratively, but also conceptually. Today, the term 'image editing' replaces the earlier term 'image manipulation' for the same process, i.e., the creative intervention in a photographic process previously aimed at fidelity to the image. The vision of the 'creative' pioneers has come true, and the photographic process itself has become a subject, an object of its own kind. The 'medium' of photography is an 'object' and a discursive subject of artistic and scientific forums.
Hein Gravenhorst's PHOTOMECHANICAL TRANSFORMATIONS can now be considered a significant model of this movement. With their geometric clarity and transparency, they set a historical sign. They were created with technical means at the height of their time, with optics, chemistry, and a sophisticated trick film mechanism according to the 'state of the art' at the time, in which the computer did not yet play a role. They are unique works based on analogue multiple exposures on a photochemical image carrier. Their aesthetic concept is openly revealed and shows designs that are coherent in themselves. Their process of creation is comprehensible step by step. There are no metaphysical shadows."
Text written by Gottfried Jäger
