Motion Picture News (Sept-Oct 1918)

2072 (Equipment Service) Motion Picture News The film that first made motion pictures practical is easily identifiable by the words "EASTMAN" AND "KODAK" on the film margin. EASTMAN KODAK CO., ROCHESTER, N. Y. Entrust the developing and printing of the films to Evans and avoid disappointment as to quality. Our service has reached the highest stage of perfection in every detail. (Ask those ice serve.) EVANS FILM MFG. CO. 416-24 West 216th Street New York City Telephone: St. Nicholas 3443-44 "NEWMAN" BRASS FRAMES AND RAILS Frames, Easels, Balls, Grilles, Signs, Chopper*, Kick Plates. Door Bars A FEW REASONS why " NEWMAN " METAL FRAMES have been chosen by all the big circuits and best class of theatres. 1 — Because the constant exposure to all sorts of weather conditions cannot affect " NEWMAN " NON-CORROSIVE METAL, FRAMES. 2 — Because of their richness in beauty and design, they liven the entrance and render the lobby more Inviting than any other kind of frames. 3 — Because they will outlast a dozen wood frames. They are practically un-wear-out-able. INSIST ON THE NAME " NEWMAN " WHEN BUYING FBAMES Write for New 1918 Catalog THE NEWMAN MFG. CO. Established 1882 717-19 Sycamore Street, Cincinnati, Ohio 68 W. Washington Street, Chicago, Illinois Canadian Representative — J. T. Malone, Rialto Theatre Bldg., Montreal, Canada Pacific Coast — G.A.Metcalfe, San Francisco, Cal. W\ manufacture the frames in various finishes which donot require j-nlishintj cased in lead to prevent the fogging of the negative film stock, and it is also customary to have a partition covered with sheetlead between the camera and the tube from which the X-rays emanate, the subject being also on that side of the partition and the intensifying screen (upon which the camera is focused) being located in an opening in its center. While the camera casing is in a measure transparent to X-rays, the photographic objective is quite opaque to radiation of such short wave-length, when judged by the usual standards of photographic intensity, or rapidity, and an objective made of quartz is required in this class of work, in combination with the most rapid negative film obtainable. Even then sufficient exposure in the negative images can hardly be secured at the usual cine taking rate of 16 pictures per second, and such films are most all photographed at a greatly reduced speed. To protect the subject from excessive action of the X-rays, which, as is well known, can cause serious and irremediable burns, the French workers connect the tube circuit with a circuit-breaker controlled by the camera crank, which shuts off the radiant while the camera shutter is passing the objective. Micro-cinematography is carried out in identically the same way as ordinary photo-micrography, although more difficult of successful accomplishment on account of the small dimensions of the cine image, which requires painstaking focussing, indeed, in the case of high power work. While both horizontal and vertical cameras are extensively used in ordinary micro-photography, the vertical arrangement seems to be preferred by most workers in micro-cinematography. The draw-tube of the microscope is connected to the lensopening in the camera front, the photographic objective having been removed. For most classes of work the eye-piece, or ocular, of the microscope serves as the objective and projects the magnified image onto the film at the exposure plane of the camera. A projection eye-piece is perhaps to be preferred in all classes of micro-photography where an eye-piece is used to project the image onto the sensitive photographic surface, but fine work can, and has been, done with the ordinary oculars. For some classes of work the magnified image is projected to the exposure aperture of the camera without the intervention of an eye-piece. It is a most necessary convenience for the cine camera used in micro work to be provided with a small bellows attached to the front-board around the lens opening. This bellows has its own front-board, to which the draw-tube of the microscope is attached, and should be capable of extension by rack and pinion. By adjusting the distance between the microscope and the exposure plane in this way the image on the film is brought to the desired size, after which the final focusing is accomplished by the fine adjustment of the microscope. To shorten exposures the illumination must be critical, i. e., an image of the illuminant must be focused upon the specimen on the stage, or as nearly so as is consistent with an evenly illuminated field. Wide-angled cones of light and objectives of high N. A. give the best results when photographing minute structures, for when narrow cones are used diffraction bands are liable to surround small details in the image, and false markings, not present in the original object, are also liable to appear. While a wideangled cone from the condenser sometimes floods a microscopic specimen with light to the extent of obliterating details in the image, this is generally counteracted in micro-photography by the use of contrast color filters, which have to be used in a great many cases in order to give contrast to the resultant photograph. To get the full benefit of color filters panchromatic negative film has generally to be used, but even with the available film stock of this variety it is difficult to secure good micro-movies of some objects, owing to insufficient contrast, and a slower, more contrasty negative stock (preferably color sensitive) would be desirable. Microscopists are well aware that by the use of special apparatus in conjunction with the usual microscope particles much smaller than the theoretical resolving limit of half a wave-length may be observed and photographed. We have applied the SiedentopfZsigmondy method of narrow slit, dark-field, illumination to the photography of ultramicroscopic particles in colloidal solutions with the motion picture camera, and w;th proper appliances there seems no limit to the smallness of a particle which can still be photographed, provided it reflects enough light to impress the photographic film. If, however, these ultramicroscopic particles are to be seen as individual particles they must be separated from one another in the solution by a distance of at least a half wavelength of the observing light.