At one time the term photogram was used in a limited way to describe the consciously artistic photograph as opposed to the mere mechanical record. Nowadays, however, the word is generally reserved for pictures of an abstract kind which, though made on photographic material, are created without the use of a camera.
History of Photograms
In its simplest form the photogram is a direct shadow pattern formed by flat objects placed on the sensitive material during a brief exposure to light, and the image thus produced is a negative silhouette: white on a grey or black ground. Josiah Wedgwood (1730-95), at the end of the eighteenth century, found that he could reproduce the form of a leaf in this way on paper bathed in silver nitrate, but his "sun prints" were not permanent for he knew of no way of desensitizing the paper afterwards. Later Talbot made permanent "photogenic drawings" of plant forms and pieces of lace in the same way, and by using the first print as a paper negative he was able to turn the image into a positive silhouette.
These experiments were, however, merely stages in the early development of photography and it was not until many years later that the aesthetic possibilities of these simple shadow patterns began to be appreciated. Inspired by cubism, Christian Schad in 1918 elaborated the technique by placing strips of torn paper, etc., on the sensitive material to produce overlapping shadow patterns that rather resembled the collages made by the painters. Further developments came in 1922 when Man Ray and L. Moholy-Nagy made their "rayographs" and photograms, using not merely opaque flat objects but also three-dimensional and translucent ones and recording the shadow patterns of varying sharpness produced by them.
Since then, the technique has been further extended and the word photogram has come to be used not merely for these comparatively simple shadow pictures, but for all sorts of abstract pictures made on photographic material by any method at all- including the deliberate (or sometimes, no doubt, accidental) fogging or staining of the print. In fact, anything is fair in photogram making and no method is barred so long as no camera is used. But there would seem to be no reason why one should not project a camera-made negative of a suitably abstract kind to form part of the photogram image, so it is clearly impossible to draw a sharp dividing line between the photogram and, say, the abstract photograph.
The making of a photogram is an uncertain business: it is not easy to tell beforehand how it will turn out, but therein lies the fascination. After a series of dull and disappointing results, the surprisingly beautiful effects that come quite unexpectedly can more than make up for the failures.
Films or plates can, of course, also be used; but large ones are costly and small ones are limiting. But there is the advantage that they can be enlarged to make positive versions (or via contact transparencies, enlarged negative prints also). But photograms made direct on thin paper can also be duplicated by using the original as a paper negative. A certain amount of the texture of the paper will be evident in the photogram, but this will not usually detract from the result and may, indeed, enhance it.
Literally anything may be used to form the shadow patterns, e.g: paper of varying degrees of translucency. cut or torn to suitable shapes, coiled or crumpled paper or Cellophane, bits of gauze, perforated zinc, bent wire, string, thread, hair, a feather, a watch spring, an electric bulb, or a kitchen implement. Solid objects, if light in tone, will, when not in all-over contact, introduce a partial greying of the white shadow pattern where the light has crept in or is reflected from the underside.
Polished objects will throw out spots and lines of light and, if the exposure is short enough to leave the background fairly light, these will show up in black. Interesting effects of this sort can be got by using strips of tinfoil, curled or twisted in various ways. Somewhat similar effects are produced with glassware, e.g: a cut glass stopper, the neck of a broken bottle, fragments of glass, a condenser lens or transparent crystals. These reflect and refract the light in quite unexpected ways, producing lines and splashes of black through both white pattern and background.
The articles may be placed direct on the bromide paper, or they may be arranged on a sheet of glass with a sheet of white paper under it, so that the effects can be to some extent planned and studied. The glass can then be gently lifted and the bromide paper slid under it. This makes it easy to run off several prints, and to alter the arrangement without starting afresh each time, although the objects in question will never record completely sharply by this method. For maximum sharpness the glass used should be as thin as possible, and the exposure should be made under directional illumination, such as is given by an enlarger which is focused onto the bromide paper.
Any kind of light source can be used, from a match to a small spotlamp. The character of the shadow shapes will depend on how concentrated the light is, on its distance from the objects and the angle at which it strikes. An electric torch bulb (preferably without reflector) makes a very useful tool because it can be used at close quarters at any angle, either held in the hand or arranged on some improvised stand.
Softer outlines will be created by an ordinary pearl lamp, but this will have to be used farther away or exposures will be too short to control accurately.
For sharp clear-cut outlines the material may be arranged under the enlarger, with the enlarger focused sharply on the bromide paper; a baby spot will produce similar sharp effects and can be applied from any angle, but unless it is very small indeed it will have to be a good way off.
More complex patterns with cross shadows result if two or more lights are used, or the same effects can be got by making multiple exposures with a single lamp in different positions. Curious ghostly effects can be produced by keeping the light moving during exposure.
Endless variations in the shadow shapes can be made by changing the angle of the lighting. This is especially so if the articles stand up well from the glass and are only in contact with it at certain points. With low slanting light the shadows stretch out and widen into fantastic shapes. Bent wire and glass articles are particularly suitable for this treatment. Vaguer patterns are produced if the objects are raised some distance above the paper, e.g: by a second sheet of glass.
Soft all-over patterns can be introduced with netting, or by sprinkling very small articles (say hypo crystals or sugar, or drops of water) over the raised glass.
The pattern need not, of course, be confined to white shapes on a grey or black ground: by interrupting the exposure and then taking away some of the articles, their shadows will be greyed to a depth of tone depending on the length of the further exposure. When the articles or their shadows overlap this method is extremely effective. The tone of the background also can be varied by holding back parts, as in enlarging. A photogram may be in bold black-and-white or, at the other extreme, in white and pale greys.
And as all is fair in photogram making, the print can be partially fogged or even deliberately stained by exposing it to light before it is completely fixed. Films or plates can also be fogged during development to cause solarization of the image.
There is still another way of making photo-grams with the enlarger not yet mentioned: it might be called the method of the "hand-made negative".
Cut-outs and various small articles are formed into a design on a small piece of glass which is slid into the position usually occupied by the negative carrier of a vertical enlarger.
Obviously the articles have to be small and with expressive outlines, and many if not all, should be transparent in some degree, e.g: pieces of very thin paper, Cellophane, old film, a mica washer out of an electrical fitting, a small feather, hairs, thread or gauze. Unfortunately, many enlargers are unsuitable for this technique because there is not a big enough gap for such a thick "negative" to be slid into place.
A further extension of this idea which has been applied effectively by some artists is literally to draw the negative by etching on a blackened plate or by applying pigment to a clear plate, and printing the result.