The Independent Film Journal (1952)

Three-Dimension Pix Require Bright Projeetion Illumination By Edward Lachman, President, Carbons, Inc. Third-dimension projection has burst upon the motion picture industry in a blaze that is causing as much confusion as existed in the first days of “talkies.” A dozen new processes have been announced within the past few months and studios are turning out new pro¬ cess films at a prolific rate. Along with its great improvements in life¬ like picture projection, 3-D has presented many new problems to the projectionist and theatre operator. These problems include the added direct reflectively caused by the metalized screen, the necessity of perfect interlocking projec¬ tion of the two cameras, larger reels to elim¬ inate intermission, larger screens and the use of Polaroid filters and viewers. But foremost among the new problems is the need for better carbons and ares which will give brighter, more constant and longer burning light. In order to have a pleasant projection, and a satisfied patron, the incident light on the screen should not be less than 12 foot candle. That is to say that the brightness of the screen should not be less than nine foot 1amberts. These accepted minimum standards are to be used whatever the projeetion system is — stereoscopic (three-dimension), or twodimension wide-screen pictures. In the system where the three-dimension illusion is created by some artificial devices (Cinerama), there is no unusual absorption of light. However, the total flux of light is dispersed over a much wider surface. There¬ fore, in order to obtain a minimum bright¬ ness, the light output of the projection lamp must be increased. In reality, there seems to be only two 3-D systems now in use: Tri-dimensional (Nat¬ ural Vision, etc.), and the illusion of three dimension (Cinerama, etc.). The true three dimensional system, which calls for a polarizing filter in the light path, causes much absorption of light through the use of these filters. The loss suffered through the polarizing spectacles worn by the patron must also be considered. The loss of light through the filter is ap¬ proximately 50 percent, while the loss through the spectacles is 10 to 15 percent; resulting in a total loss of not less than 60 percent. It is generally accepted that a metalized screen must be used for polarized projection. The metalized screen keeps the light polar¬ ized after reflection, while the common matte Finance Plans Layout Land Federal State and Local Regulations Box Office Projection Booth Concession Booth Fence Speakers Wiring Screen Tower Overflow Area Projectors Soundheads Amplifiers Power Plumbing Grading 3-D Interlocks Introduced The choice of either a mechanical or an electrical interlocking system for adapting equipment to the synchronous projection of stereoscopic third-dimensional films was made available to exhibitors by the Motiograph company. The mechanical system allegedly intercon¬ nects the soundheads through gear reduction boxes, can be used with any make or model of mechanism, except obsolete units. The electrical system is more costly, but can also be used with any type of mechanism, the maker claims. surface will depolarize the picture and cause loss of depth. Figures given for several metalized screens show a noticeable improvement of re¬ jected light along the axis and a 15 to 30 1 degree angle along each side of the axis. ' This is not the most desirable result because patrons on the sides of the theatre or near the screen will see a duller picture. Long, deep theatres are best for this pro¬ cess because metalized screens reflect the pic¬ ture on a narrow polarized beam. The special reflecting characteristics of the ' metalized screen do not affect the percentage of lost light mentioned above. It affects only the repartition in the theatre of the light received on the screen, and then transmitted to the patrons. Light Increase Needed The 60 percent light loss indicated above shows that in order for the patron to see a bright, clear picture, the power of the are in the projection lamp should be increased tre¬ mendously. Of course, the amount of light is limited by the ability of the film to withstand the increased amount of heat in the projeetion head. Fortunately, lamp manufacturers are now overcoming this problem with newer ^ and more improved lamps and cooling sys: terns. The need for more light makes it impera¬ tive that the best available carbon be used in the projection lamp. Both the Lorrainesuper 8mm. Orlux carbons, for those theatres which can not adapt to the larger carbon, and the 9mm. Orlux super-charged carbon, for which Carbons, Inc., is sole representa¬ tive in this country, has been engineered to give the best all-around qualities necessary for 3-D projection. Advantages Cited The new 9mm. Orlux features not only a unique core but an improved formula for this core which gives it a larger gas ball, moreintense light and a greater burning period (more than 60 minutes), which makes it more than adequate for the new longer reels. In addition, it permits a wider distribution of light on the screen than previously ob¬ tained and a constant even brightness which' is necessary for the simultaneous use of two cameras. Carbons, Inc., and its associates, are look¬ ing now to engineer and develoj) even betters carbon products in order to keep abreast of the advances which are taking place in the’ motion picture industiy. They hope to con¬ tinue to provide the greatest economy fori theatre operators and the ultimate in view¬ ing pleasure for patrons. Ballantyne solves the ba^sic problems with the package plan Ballantyne has pioneered the "package idea” for drive-in theatre operations that make it possible for you to sit down with a com¬ pany representative and get the whole picture of the hundreds of important details that go into outdoor theatre operations. You get the entire equipment cost picture. We furnish you with comprehensive free plans, tailored to your land. This in¬ cludes buildings, tower, wiring etc. It’s the safe and certain way to make a large investment. Contact a Ballantyne representative for the whole picture in a package . . . or write to THE BALIANTYNE COMPANY 1712 Jackson Street Omaha 2, Nebraska, U.S.A. 30 THE INDEPENDENT FILM JOURNAL— March 21. 1953