International photographer (Jan-Dec 1935)

Tiventy-six The INTERNATIONAL PHOTOGRAPHER January, 1935 STUDY IN MOLECULAR ATTRACTION The one hundred and five pounds of Miss Alberta Kaesser is suspended by nothing more than the molecular attraction between the surfaces of two pieces of highly polished optical glass, so accurately flat that they will resist a separating force of 95 to 100 pounds per square inch. The surfaces are accurate to within a millionth of an inch. These test glasses, made by Bausch & Lomb, were part of an exhibit for the annual meeting of The Optical Society of America at the Bureau of Standards, Washington, D. C, October 18-20. APPLICABILITY OF STEREOSCOPY TO MOTION PICTURES (Continued from Page 2) merits of the subject will demonstrate the problem confronting the experimentor in this branch of motion pictures. Some may seek to discount our pessimism by reciting the fact that they have witnessed demonstrations of stereoscopic motion pictures. This is true, and in reviewing the various methods by which those pictures were made we consider the obvious mechanical and mathematical propositions under which experimentors have agreed for years. We refer to the necessity of the picture corresponding to the vision of the right eye being neutralized, while the left functions, by means of shutters or spectacles, each eye being furnished with mediums of complementary colors; both expedients depending upon the persistence of vision in associating the two images in the brain, and in lieu of the prisms or reflectors of long established methods. These pictures have been interesting but costly experiments and of no commercial value, for several reasons. First, because they depended upon the co-operation of the audience, and the public is a cruel, impatient patron or partner when it is expected to share the difficulties of an enterprise. Secondly, they represent a very poor patent protection. Most of the patents granted on devices for making stereoscopic motion pictures show very little originality and nearly all embody the first principles of the early days, even of the times when drawings were viewed in simple instruments like Elliot's stereoscope. The only unique device shown is one based on the oscillation of the eye and produces only pseudo stereoscopy. Many other experiments have been suggested by these pseudo effects, such as the oscillation of the eye in monocular vision or the rapid and even change of parallax, observed in pictures taken from an aeroplane circling over tall buildings or from a boat moving along a winding stream, or from da Vinci's effect of viewing a picture from the proper point of sight. These effects have been attempted, in motion pictures, by placing the camera on a platform moving in an arc, the radius extending somewhere back of the set, by which means the foreground objects are continually measured against those in the background. Other experiments provided queer lenses placed in front of the main objective or by reflecting the image into the camera, special screens that insist on one person in the audience sitting in the propsr place, all of which are worthless propositions. Through ignorance of the subject, there have been misrepresentations of millions of dollars having been spent in perfecting a system of stereoscopic motion pictures, and it is due those concerned in that project to state that we do not believe there has been any claim of true stereoscopy in a wide range picture taken with a single lens or without the aid of optical devices for the observer. The name, "Natural Vision," has probably been erroneously used in designating a monolens picture covering an angle more nearly equal to the range of the human eye than that of the standard motion picture. Even this system comes within the realm of artistic judgment as to how much of a subject should be presented, to furnish excellent composition, for there is no pictorial value in scattering our vision over a tremendous area. It is interesting to observe that the difficulty lies not in the taking of stereoscopic motion pictures but that the real problem is in projecting them, which brings us to a consideration of the much disputed points suggested in sections three and four, i. e., the psycho-physiological elements. Outside of the body, and even as far as the two retinae, we have a satisfactory explanation of the phenomenon of stereoscopy, arrived at by deductive reasoning, aided by many branches of mechanics and mathematics; but when we leave the retinae we are to suppose a sort of psycho-physiological stereoscope set up in the brain, which at present is conveniently explained by assuming that the optic nerve transfers the retinal stimulus to the brain. We are confronted with the proposition of two flat images, similar to those on the ground-glass of an ordinary camera, falling upon the retinae and associated in some manner in the optic thalami, then transmitted through the optic radiation to the visual centers and other parts directly connected with the perception of this Please mention The International Photographer when corresponding with advertisers.