Motography (Apr-Dec 1911)

18 MOTOGRAPHY Vol. V, No. 4. place each of them in a projection lantern, in such a way that they can be superposed upon the screen, we' shall obtain thereby a single image. It will always be a little light and soft, as the superposition cannot be effected accurately, the perspective not being the same for each of them. It is a question now to make each eye see the one of the two images proper to it. To this effect Mr. D'Almeida conceived the very ingenious idea of placing green glass in the lantern in front of the image having the perspective of the right eye, and a red glass in front of the other image. As green and red are complementary colors, the result was not changed upon the screen; there was a little less light, that was all. But if, at this moment, the spectator places a green glass before his right eye and a red one one before his left, he will find himself in the condition desired for realizing the effect sought. Each eye then sees only the image responding to the coloration chosen, and, as it is precisely the one which has the perspective proper to it, the relief ap ever, apparently never materialized. So far as public exhibition is concerned, it would never be successful, because it imposes on the audience the unpleasant requirement of wearing special glasses. As stated above, the requirement for stereoscopic projection is that each eye must see only its particular one of the two images. This would seem effectually to dispose forever of the possibility of developing a practical method for placing stereoscopic images on a screen, to be viewed with the naked eye. But in the event that we cannot obtain the real article we are in search of, an imitation sometimes serves almost as well. For example, we can often perceive a purely imaginary stereoscopic effect by the simple process of gazing fixedly at a good photograph with one eye, keeping the other closed. In this case the effect is probably obtained because we are subconsciously aware that one eye cannot perceive relief ; and since we are using but one eye, the absence of relief is not evident and our senses accept its presence BACK DROP SCENERY wincjs /•^ t z Id z ~ _____ O 0 13 J <_ __ — w u ___— — z <o _____ — < a k □ PROJECTOR ^— FRAM STAOjE Diagram of "Pepper's Ghost" as Adapted to Messter's Alabastra System. pears immediately. The effect is striking. We perceive a diffused image upon the screen with the naked eye, but as soon as we use one special eye-glass the relief appears with as much distinctness as in the best stereoscope. One must not, for example, reverse his eye-glass, for if (things being arranged as we have said) he looks through a red glass before his right eye, and through a green one before his left, it is the image carrying the perspective designed for the right eye that will be seen by the left eye, and reciprocally. There is then produced, especially with certain images, a very curious effect of reversed perspective, the background coming to the front. An assemblage of persons all provided with colored, eye-glasses would be quite curious to contemplate. The old print reproduced here represents a stereopticon seance, and shows well the effect of the two luminous and differently colored fascicles superposed upon the screen. In a preceding note upon the same subject, Mr. Hospitalier remarked that upon combining these effects of perspective with those of the praxinoscope, an early motion picture machine, we would obtain entirely new effects. This interesting adaptation, how automatically. In other words, we copy, with a single camera lens, a view which we are accustomed to observe through two eye lenses ; and conversely, on observing the result through one eye lens, we get a subconscious effect of two camera lenses. This system, however, adapts itself to. projection no more readily than does true stereoscopy, since it depends upon a special use of the observer's eyes. There has lately come into prominence, however, a system which, while in no sense truly stereoscopic, nevertheless manages to secure an effect which has all the apparent qualities of projection in relief. The new system has been developed by Messter, and is called by him "Alabastra" because the projected images are white, like miniature marble statues. Alabastra is motographic. The invention has been shown in many of the great cities of Germany, where it has created a considerable sensation, as well as in England and this country. The studio is fairly well illuminated, quite well enough to be able to read, and this amount of light does not in any way destroy the illusion. The invention is in principle an application of "Pepper's ghost" to cinematography, but so modified as to give a stereoscopic effect. This is obtained