Journal of the Society of Motion Picture and Television Engineers (1950-1954)

3-D, Stereoscopic Motion Pictures: The design feature here is reality through the perception of depth. Present-day 3-D systems utilize two cameras, one for the left-eye image and the other for the righteye image, simulating the process of normal vision. Two projectors, interlocked to run synchronously, are then used with polarizing filters to project two separate images, one for the left eye and the other for the right eye. Viewing filters permit each eye to receive its own image as viewed originally by the two cameras. The brain fuses the two images and the flat screen then provides images with apparent depth. Mr. Norling then listed the requirements for 3-D showings : 1. A metallic coated screen, 2. Method of synchronizing the two projectors and their shutters, 3. Lenses matched for focal length and distortion, 4. Equal light output from each projector, 5. Light output increased from each projector by roughly a factor of 2, 6. Larger magazines and reels for acceptance of several intermissions. Mr. Barnett then asked how the Society could best serve the interests of the exhibitors. The reply to this boiled down to three essentials : 1. Explain in laymen's language the new technical developments and future developments as they occur. This would, in itself, eliminate much confusion in the trade. 2. Supply unbiased answers to the questions facing the exhibitors. 3. Establish standards which will a. aidinterchangeability; b. retain as much of present equipment as possible; c. prevent newly purchased equipment from becoming obsolete; and d. permit readily interchangeable projection of either 2-D or 3-D motion pictures. In regard to the first item. Mr. Nemec advised the group that the Society is in the process of preparing just such a story, which should be available in the near future. As for standards, he stated that the closest cooperation and liaison is being maintained between the SMPTE and the MPRC and that the above-mentioned standards goals would undoubtedly be used as a guide. The remainder of the conference was devoted primarily to expressing the most pressing questions before the exhibitors. These were listed as follows: Pertaining to 3-D On Screens \ . Can an all-purpose screen be developed for 2-D, 3-D and panorama pictures? 2. Can existing screens, in good condition, be sprayed with a metallic paint to provide a satisfactory surface for 3-D use? On Lenses 3. What is the required accuracy of lens matching? On Filters 4. Is there a nonfading type of polarizing projector filter? 5. Has the projector filter been standardized? 6. Has the viewing filter been standardized? 7. Must the projector filters be artificially cooled? On Projection Lamps 8. What portion of filters' light loss must be compensated for by increased lamp output? 9. What light output differences between projectors can be tolerated? On Projectors 10. What is the probable size of future magazines and reels? 11. Are special arc supplies required for continuous projection? General Questions 12. What are the chances of 3-D without viewing glasses or with a single projector? 13. What are splicing instructions for 3-D films? 14. Are special rewinds and synchronizers needed? 15. Explain apparent decrease in picture size. 16. Explain in simple terms the fundamental characteristics of the new developments in motion pictures. 17. Explain stereophonic and binaural sound. 18. What can an exhibitor safely (to preclude rapid and expensive obsolescence) do now to prepare for scheduled 3-D showings? 191