Reel and Slide (Mar-Dec 1918)

.1 Any questions pertaining to the projection of films and slides on the screen will be answered by this department. Address "Projection," Reel and Slide, 418 S. Market St., Chicago. If an answer by mail is desired, enclose stamped envelope. All About the Projectors (Many requests reach this office for information concerning the various types of moving picture projectors. Reel and Slide will print in this department a complete description of each machine now on the market for the benefit of its readers. Next month the Uniscope projector will be described. — Editor.) The DeVry Portable Projector is contained, in a strong, but very light, pressed steel suitcase, seventeen inches square by seven inches deep, covered with imitation leather and lined with asbestos. The compartment containing the motor, the electric wiring and the incandescent source of illumination, is divided from the compartment containing the mechanism and film by an asbestoslined metal division. The source of illumination is a 400-watt Tungsten filament lamp, working through an especially designed optical system consisting of a spherical mirror reflection, placed behind the lamp. The incandescent lamp is what is known as the standard G-30-400-watt bulb. It is about four inches in diameter and its front edge sets almost in contact with a miniature piano convex condenser two inches in diameter. The front side of this condenser sets lyi inches from the film. The objective lens is a special type made for the DeVry Corporation. This lens consists of three units — two positives and one negative, all cemented together. This lens gives a sharp definition and a comparatively large opening, thus making available a maximum percentage of the light delivered through the film by the condenser. In other words, this type of projection lens retains sharpness of definition and at the same time minimizes the loss of light due to the spread of the ray beyond the aperture. The lamp itself is contained in a seperate, fireproof metal compartment, which has ventilation direct to the outside air. At the bottom of the lamp compartment is the electric motor, which is of the universal type, hence can be used on either alternating or direct current. Behind the motor, not shown in the illustration, is an opening in the case. On the further end of the motor shaft is a small fan which runs 5,700 revolutions per minute, pumping air up through the lamp compartment, thus dissipating the heat generated by the Tungsten filament illuminant. The motor is belted to the mechanism in the usual way, and has speed regulation sufficient to take care of all reasonable requirements, the regulation being accomplished by means of a field rheostat controlled by a knob on the top of the case. What corresponds to the upper reel and the take-up reel in a standard projector are on one spindle, the outer reel, which is visible in the illustration, being the one corresponding to the upper reel in a standard projector. There is a simple arrangement by means of which take-up tension may be adjusted to any required value. The path of the film through the machine may be traced in the illustration. The l.irge knob on top of the case to the right of the handle is the framing device. The knob on the right-hand side near the top is the focusing screw. The electrical connection is made by means of a motor attachment plug on the back of the case, the same being flush with the side of the case. The mechanism is small, compact, sturdily built and very ingeniously arranged. The frame is of pressed steel, all one piece, including the lens holder. What corresponds to the upper and lower sprockets in the standard projector are provided with double idlers, which gives a maximum grip of the film by the sprocket. The tension is similar to that used in standard projectors, being pivoted, so that the tension on either side is always the same. The aperture plate tracks may be easily replaced when worn. We have witnessed the projection of a very excellent picture by the DeVry inachine under adverse conditions of light. Also saw the machine started running with the lamp burning, the case lifted up, turned down, sidewise and in every conceivable position, the machine still grinding away projecting a picture alternately on walls, ceiling and floor. It is not a theater machine, nor are the makers seeking to sell it for use in theaters. It is for the use of traveling salesmen, for use in factories, homes, churches, class-rooms and work of that kind. It uses a three-wing shutter. Under ordinary lighting conditions, and with a proper screen, the DeVry will deliver a very acceptable picture up to eight feet wide. This size may be expanded under some conditions to as large as ten feet, with good results. The company prides itself on the simplicity of the mechanism, which contains but four gears, all told, and the fact that it is as nearly foolproof as any mechanism can be made. What kind of equipment is necessary for school work? J. B. M. Answer: That depends upon its use. For a large assembly room a professional machine should be used, such as the Simplex, Powers or Motiograph. If you wish to use slides and moving pictures the semi-professional machine, weighing about 100 pounds, which is equipped for both, should be purchased. For average class-room work a portable machine is best and most convenient. These weigh about 25 pounds and can work a portable machine is best and most convenient. These weigh about 25 pounds and can be attached to any lamp socket. Do we need a booth? Harris. Answer: When using less than a 5-ampere Mazda light a booth is not necessary. Celluloid film will not burn with that low amperage, hence machine can be stopped at any point and a talk given on the picture. When more than S-ampere current is used, a booth is required. In this case always meet underwriter's requirement. Get a copy of the "New Electrical Code" from the city electrical inspector or write to your secretary of state. This code gives full requirements. * * * Can anyone operate a machine? P. J. M. Answer: Any 15-year-old boy can soon learn to operate a machine with safety. In some cities the operator must be at least 18 years old and secure a license by taking the necessary examination. How long does it take to run a picture? B. L. J. Answer: A full reel is 1,000 feet. Pictures are taken to run at the rate of two minutes per 100 feet, or 20 minutes per reel. Theaters usually run in 15 minutes. For class-room and educational purposes, 25 minutes should be taken. * « # Can you run slides and films on the same machine? B. Answer: Most professional and semi-portables use both. Portable machines are not made for slides, as the films can be stopped at any point and a still picture shown. 26 Capital Merchandise Go. Enlarges Organization THE Capital Merchandise Company, formerly at 525 South Dearborn Street, Chicago, and one of the best known exchanges and supply houses in the city, has moved into new quarters at? 538 South Dearborn Street. The general expansion of the business is given as the reason and the need for a greater amount of space. The Capital Company has acquired a large supply of educational pictures of the highest grade and has arranged for many additional subjects of a wide variety. The Educational Department will serve schools and churches in making up their programs and in the selection of projectors and equipment. The educational reels now available through this company, include pictures on travel, scenics, industrial subjects, agriculture, history, classic drama, geography and many technical films which are b'.'ing enthusiastically accepted by educators. Mr. Pearlman of the Capital Company says the move is necessary because of the increasing demand upon his organization. "We feel that our experience in the theater field qualifies us to serve the educational institutions effectively," said Mr. Pearlman, and we have already acquired by outright purchase, a considerable library of educational pictures. We are adding to this list daily. Each picture has been selected for its true value. We believe it is the exchange's duty to protect the institution from poor quality of reels. Therefore, we accept nothing that is not right up to the mark. "For some time, we have seen the need of an educational department. The sale of projectors in this field is an indication that a proper amount of attention given to the peculiar needs of the schools, will well repay itself. "It is our desire to establish a reputation in this new field and our new and enlarged quarters will assure that." Ward Modern Bakeries Filmed as Educational Feature A THREE reel industrial picture, depicting the making of bread, from the growing of the wheat in North Dakota to the consumption of the finished product in New York, has been filmed by the Ward Baking Company of that city. This picture, besides being an advertisement for the Ward products, furnishes a picture of considerable educational value. The modern bread-making machinery in action, sanitary conditions which characterize the modern bakery and the conservation of wheat flour by eliminating all waste is portrayed. The reels have been shown widely in the East in theaters and educational institutions.