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,[1] while fully-exposed areas are black in the final print.

The technique is sometimes called cameraless photography.[2][3][4] 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.[5]

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").