Photogram

A photogram is a photographic image made without a camera by placing objects directly onto the surface of a light-sensitive material such as photographic paper and then exposing it to light.

The usual result is a negative shadow image that shows variations in tone that depends upon the transparency of the objects used. Areas of the paper that have received no light appear white; those exposed for a shorter time or through transparent or semi-transparent objects appear grey, while fully-exposed areas are black in the final print.

The technique is sometimes called cameraless photography. It was used by Man Ray in his rayographs. Other artists who have experimented with the technique include László Moholy-Nagy, Christian Schad (who called them "Schadographs"), Imogen Cunningham and Pablo Picasso.

Variations of the technique have also been used for scientific purposes, in shadowgraph studies of flow in transparent media and in high-speed Schlieren photography, and in the medical X-ray.

The term photogram comes from the combining form phōtō- (φωτω-) of Ancient Greek phôs (φῶς, "light"), and Ancient Greek suffix -gramma (-γραμμα), from grámma (γράμμα, "written character, letter, that which is drawn"), from gráphō (γράφω, "to scratch, to scrape, to graze").

History

Prehistory

The phenomenon of the shadow has long aroused human curiosity and inspired artistic representation, as recorded by Pliny the Elder, and various forms of shadow play since the 1st millennium BCE. The photogram, in essence, is a means by which the fall of light and shade on a surface may be automatically captured and preserved.

To do so required a substance that would react to light.