Amateur Photographer & Cinematographer (1933)

| k AMATEUR PHOTOGRAPHER it? 6 CINEMATOGRAPHER a December 6th, 1933 Shadowgraph Puzzle Pictures A CHRISTMAS PHOTOGRAPHIC NOVELTY. By W.C. R. ONCE again the party season arrives, and the annual hunt for amuse¬ ments and games for the guest begins. To some this may be a difficult problem, to others, no problem at all, but in any case a puzzle picture competition is a useful solution. The puzzle picture has been suggested several times as an interesting amusement, and consists of photographing various objects in an unusual manner with, as they say in legal circles, “ intent to de¬ ceive.” While this is a very pleasing occupation it demands a considerable amount of both time and material. Negatives have to be made, developed, enlarged, etc., and when a dozen or more are involved this becomes quite a consider¬ able task. A shadowgraph puzzle pic¬ ture, however, is simplicity itself. All that is required is a packet of bromide paper and the necessary developer and fixer. Twenty or more pictures can easily be made in me evening. The object is to photograph not the article but its shadow. Lay a piece of sensitive paper on a flat surface and arrange the object so that it casts a shadow on the paper, then expose. The result, as will readily be appreciated, will be in negative form, i.e., the shadow white and the rest ack . T h shadowgraph. My own method of working, which may be of assistance, is as follows : A half-plate sheet of bromide paper is laid on the bottom of a large, upturned wooden box, which serves as a stand. and can be moved and used in any part of the room. The paper is then masked to give a white border and the objects arranged for the required shadowgraph. This, naturally, is carried out under an orange safelight, which, in my case, is of the type that screws over an electric lamp. The exposure is given by unscrewing the orange cover for the requisite period and screwing it back again at the end, when everything is ready for developing the picture. Other methods of making the exposure with an electric bulb will readily occur to the reader. Merely switching the light on and off is the simplest, but, in any case, the light must be fixed in relation to the print. Any movement or swing of the lamp will caused a blurred image. One way of disguising the subject, to create a puzzle, is by arranging it or the lighting so that an unusual or peculiar shadow is cast. Another suggestion is to use articles whose shadows are difficult to recognise. Glass is very useful in this connection, and tumblers, bottles, wine-glasses, etc., can be arranged in innumerable different ways to give some extremely puzzling results. It will be found that glass objects cast not only a shadow but also high-lights. If the exposure is adjusted to give a background of neutral grey the shadows will be white and the high¬ lights black, the result often being absolutely unrecognis¬ able. When solid articles are_ being shadowgraphed actually resting on the paper, as can frequently be done, a fairly long exposure should be given. Then the impression of the subject will remain white but its cast shadow will develop up a light grey. This will also help to confuse the solver. The question of exposure is largely a matter for experiment. I found that using a 25-watt electric lamp, five feet from a vigorous bromide paper, an exposure of about 30 seconds was required. With glass objects this exposure was halved. It will be obvious that, as the actual shadow is used to make the image, only small objects can be utilised for this purpose. The shadows of small parts of large articles, however, 36 528