International projectionist (Jan-Dec 1953)

New Synthetic Film Base by Du Pont Detailed ANEW synthetic base for motion picture film, said to be much stronger than the present types of acetate safety film base, will be manufactured by the Du Pont Co. at a new fac • The NEW. improved, positive method of permanently patching all types and makes of film — 8-mm. 16mm, 35-mm, Trucolor. Technicolor, Kodachrome. Nitrate and Safety Film. Used and endorsed by Projectionists in countless theaters. Specifically for Lasting Patches. ESSANNAY ELEC. MFG. CO 1438 North Clark Street Chicago 10, Illinois tory unit to be built at the firm's Parlin, N. J., plant with production beginning in 1955. The Du Pont announcement states: "Extensive tests have shown that the new base, identified as a polyester and related chemically to the Du Pont textile fibre, Dacron, is several times stronger and has much more dimensional stability than any of the present types of safety film base, and has comparable flame resistance. For use in motion picture film, this new polyester offers the important added advantage of reduction in film thickness, making possible greater footage per reel. Polyester film has higher clarity than conventional film bases, and appears to have better storage and aging characteristics. "The new base was developed and is currently being made in limited experimental quantities. Construction of the full-scale unit at Parlin will start in the near future, and completion and initial production are forecast for the middle of 1955. "Compared with either cellulose nitrate or cellulose acetate films, polyester has twice the tensile strength and tear strength, and can be stretched more than 4 times as far before breaking. It is virtually unaffected by immersion in water or changes in humidity. In a test of folding endurance, polyester film with . . . for its perfection of image quality and co/or correction . . . for sharpness and contrast . . . for maximum light transmission (speeds up to f 1.9) ... for its hard, durable surface coating OVER 30 YEARS OF SKILLED CRAFTSMANSHIP INSURE PRECISION OPTICS OF DISTINCTION. COMPANY. INC. 330 IYEIL AVENUE • B O C H E S T E » , N I W YORK Exclusive Distributors: RAYTONE SCREEN CORP. ^oST^w yoRk stood 17,000 flexings, while an ordinary film failed after about 100. Polyester film showed virtually no signs ot wear after 3900 runs through a motion picture projector; perforations on standard films wore out after 1400 projections. "Because of its greater toughness and flexibility, the polyester base makes it possible to reduce the thickness of standard motion picture film from 5% mils to 4 mils (5 thousandths to 4 thousandths of an inch) , a 27% reduction. This means that the new base will significantly reduce shipping weight and storage volume per foot of film, besides enabling producers to put up to 35% more film footage on a given reel. "A 2700-foot reel of 35-mm motion picture film on 4-mil polyester base takes up the same amount of space and weighs approximately the same as a reel holding 2000 feet of film on the current standard safety base. "An important feature of the process is the fact that there is no industrial waste-disposal problem. No solvents are used in the casting of polyester base, whereas in the manufacture of conventional film base there is a definite solvent recovery problem. Excelite "135" Developed An increased volume of light at the screen, without a corresponding increase in heat at the aperture, is claimed for the new National Excelite "135" projection arclamp announced by National Theatre Supply. A feature of the new lamp is the Reflect-O-Heat unit, which passes the visible light while diverting heat rays back into the lamphouse where heat is removed through the stack. Designed to burn 10-mm Hitex carbons at 135 amperes, or 11-mm regular carbons at 120 amperes, the lamp provides increased light for 3-D and widescreen projection. For the full-hour running period of 5,000-foot 3-D reels, the 10-mm Hitex can be burned at 120 amperes or the 11-mm regular carbon can be burned at 115 amperes, the company said. Color value and intensity of the light at the screen is maintained constant throughout the full trim, without the need of manual adjustment, it was stated, by an automatic arc crater positioner. The National Excelite "135" will be sold by all National Theatre Supply branches. "Movies" first appeared in 1833 when a device called the "Zoetrope" was marketed. This consisted of a cylinder with drawings of a horse mounted on the inside. The viewer looked through an eyepiece, rotated the cylinder and saw the horse galloping. 26 INTERNATIONAL PROJECTIONIST • AUGUST 1953