Photogram

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A colour photogram of lemons and tomato stems. The background texture is enlarged paper grain.

A photogram is a photographic image made (without a camera) by placing objects directly onto the surface of a photo-sensitive material such as photographic paper and then exposing it to light. The result is a silhouetted image varying in darkness based on the transparency of the objects used, with areas of the paper that have not received any light appearing light and those that have appearing dark, according to the laws of photosensitivity. The image obtained is hence a negative and the effect is often quite similar to an X-Ray. This method of imaging is perhaps most prominently attributed to Man Ray and his exploration of rayographs. Others who have experimented with the technique include László Moholy-Nagy, Christian Schad (who called them "Schadographs"), Imogen Cunningham and even Pablo Picasso.

1 Procedure
2 History
3 Rayographs
4 Cameraless photography
5 List of main photographers who used the technique
6 External links

[edit] Procedure

Generation of a Photogram: A spatially extended light source (1) illuminates objects (2 and 3) that are placed directly in front of a photosensitive film. Depending on the object's distance to the film their shadows look harder (7) or softer (5). Areas of the film that are in total shadow (6) stay white, areas that are fully exposed to the light (4) are blackened.

Like all photographic processes, photograms require light. The most commonly used source of light for this purpose is the enlarger used in conventional negative printing, but any light source can be used, like, for example, the sun. The figure on the right shows how the image is formed. In the traditional darkroom setting, the paper is held in place using a printing frame. The objects to be used in making the image are placed on top of the paper. When a suitable composition has been found, the enlarger is used to expose the paper (tests will have to be done to check the exposure time and aperture required). Finally, the paper is processed, as normal, in print-developing chemicals, and washed and dried.

[edit] History

One of Anna Atkins's cyanotype photograms of Festuca grasses

Some of the first photographs ever made were photograms. William Henry Fox Talbot made numerous of these images (which he called "photogenic drawings") by placing leaves and pieces of material, like lace, onto pieces of photo-sensitive paper and then leaving them outdoors on a sunny day to expose, making an overall dark background and a white outline of the object used (which had blocked the light from the paper). Also in the early days of photography, Anna Atkins produced a book of her photograms, the first book of photographs ever made. These were somewhat similar to Talbot's images, in that they were exclusively images of botanical specimens (ie. plants), but they differed significantly in their appearance as they were made by the cyanotype process which made them blue in colour, as opposed to the more conventional brown/black silver halide processes. This book, a one-off, can still be seen in the National Media Museum in Bradford, England.

[edit] Rayographs

A photogram, similar to those made by Man Ray, of a number of photography-related objects

Photograms were again used to startling effect in the 20th Century by a number of photographers, particularly Man Ray, who called them "rayographs". His particular style included capitalizing on the stark and unexpected effects of negative imaging, unusual juxtapositions of identifiable objects (such as spoons and pearl necklaces), varying the exposure time given to different objects within a single image, and moving objects as they were exposed.

[edit] Cameraless photography

An image of leaves created with a scanner

There exist a large range of techniques to produce photographic images (ie. involving light) without using a camera, including the usage of scanners and photocopying machines - and this is not even including printing processes like modern lithoghraphy or photogravure. Experimentation with such techniques has become popular since the 1960s, when artists like Robert Rauschenberg started to push the boundaries of the photographic image-making process. Even other adaptations of photograms have been experimented with, such as those using birefringence, a process whereby polarized light is used instead of normal light to create an interference pattern of crystals or plastic objects, creating colourful, abstract pictures.