Motion Picture Herald (1954)

just what the doctor ordered for VistaVision WT? N ’TV-TNTJI "Brilliant Light" FOR DRIVE-INS & THEATRES using huge, wide-area screens Larce*CoRED Larger cored crater area makes possible equal brilliance on sides as well as center of screen • COOLER BURNING • UNIFORM DISTRIBUTION I Amp. Pos. Grade Neg. Grade 1 50AC 6x7 54 1-0 1C 6x7 54 1-0 1C 40 7x14 54 1C 6x9 545-20C 1 40-53 7x14 544C 6x9 545C 50-70 8x14 544C 7x9 545C j I 68-75 8x14 544IOC 7x9 545C | I 65-75 9x14 544C 7x9 545C I 75-85 9x14 544C 8x9 545C 1 80-90 9x20 552-09 5/16x9 557C | 95-110 10x20 552-09 1 1/32x9 557C ! 115 10x20 552-09 3/8x9 557C j« 1 1 15-130 1 1x20 552-09 3/8x9 557C | 130-150 13.6x22 553-01 7/16x9 557C | I 140-170 13.6x22 523 1/2x9 555C 1 170-190 13.6x22 583-08 1/2x9 555CN t voUf 1 w ’•L‘>rra" "aed on,P® CARBONS, Inc. Boonton, N. J. Better Projection A Department on PROJECTION & SOUND Choosing Picture Size and Lenses for Any Aspect Ratio By CIO GAGLIARDI in order to select the proper lenses for the production of correctly related picture sizes on a theatre screen, certain fundamental projection rules must be thoroughly understood. These rules are not original, but follow rather simple facts of physical relationships, as follows: For any fixed projection throw, the picture size increases both in width and in height when we decrease the focal length of the projection lens. For any fixed projection throw and a given projection lens, the picture width and height (aspect ratio) may be changed to a limited extent by changing the dimensions of the projector film aperture. For any fixed projection throw, a given projection lens, and a fixed aperture, the width of a picture may be increased by using an expanding anamorphic device in front of the projection lens. The amount of increase in the picture width depends on the expansion factor of the anamorphic lens (this may be fixed at a certain ratio, as in cylindrical anamorphic lenses; or variable, as in prismatic anamorphic attachments). It follows then that the only items which will have an effect on the picture size are: 1. The dimensions of the film aperture. 2. The focal length of the projection lens. 3. The expansion factor of the anamorphic attachment, if one is used. 4. The distance between the lens and the screen. For any theatre, after the screen location has been selected Item 4 becomes fixed and will not be changed. If a normal release print is used, the anamorphic attachment is not necessary. When a squeeze print is used, then the expansion factor of the anamorphic device is determined by the compression ratio of the print. CinemaScope uses an anamorphic expansion of 2to-1 ; VistaVision proposes to use an expansion of 1 j/2-to-l. Therefore Items 1, 2 and 3 are the ones which, when changed, will produce variations in the size of the picture on the screen. Every theatre presents a special problem in the selection of the various picture sizes according to whether the projection system required by the picture is Standard, Cropped Aperture, CinemaScope, or VistaVision. In order to select the proper size for each aspect ratio, and a size which will fit the theatre with a minimum of operating disruption and expense, the lens sizes and the film apertures must be manipulated expertly. In many cases calculations must he made, various, lenses tried out, and many aperture plates wasted before a suitable combination can be selected. To avoid such tedious and expensive guesswork, I have compiled a special tabulation in which are combined all the possible factors which give different picture sizes for a specific projection throw. This table is Figure 1. For this table, a projection throw of 100 feet was selected. The projection lenses from 1.5-inch to 8-inch focal-length are shown in quarter-inch steps since this is the standard American manufacturing procedure. Film aperture sizes were selected which would give the approximate normal aspect ratios of 1.33, 1.66, 1.75 and 2.00 for standard film prints. For VistaVision squeeze prints an .825 x .600 aperture was selected, which will 28 MOTION PICTURE HERALD, OCTOBER 2, 1954