Movie Makers (Jun-Dec 1928)

Photographs bj> Walter D. Kent. COLOR TRUTH IN FILM These Studies Are of the Same Three Flowers Colored, Left to Right, Violet, Yellow and Red. With Ordinary Film, Left, the Color Values Are Lost. With Panchromatic film, Center. Without a Filter, There is a Slight Improvement. However, with Panchromatic Film and Proper Filter, Right, True Color Values Are Shown on the Film. The What, Why and How ^/Panchromatic THE normal trend of progress has of late brought about a greater facilitj" and a greater assurance of constant good results in both the manufacturing and the processing of panchromatic motion picture film. The indefatigable efforts of a handful of scientists scattered in the different research photographic laboratories have finally resulted in giving to the amateur "movie maker" this film which, we dare say. will to a great extent supplant in a very short period of time the film prepared with the so called "ordinary emulsions." Since the introduction of panchromatic film in the amateur field three questions have been present in the minds of those sufficiently interested in the art not to content themselves merely with the taking of pictures, but who aspire to take good pictures. The three questions are summarized in the title of this article, "What, Why and How?" "What is panchromatic film?" "Why should I use panchromatic film?" "How should I use panchromatic film?" To thoroughly understand what panchromatic film is one must retrace in his mind the workings of photography and the limitations imposed upon him by photographic processes in general. A clear understanding of such limitations and natural rulings is essential to success. The ideal scope By Joseph A. Dubray Technical Editor of A merican Cinematographer of photography is to obtain the image of an object similar in all its aspects to the object itself. First a similarity in shape or form, second a similarity in color. The exact reproduction of the shape of an object includes, of course, the exact reproduction of several objects which together form a scene and consequently the exact reproduction of their relative position in the scene itself. This first requirement of photography pertains to the optical branch of the science. Let us suppose, for instance, a pastoral scene with a tree in the foreground, a grassy field beyond it, cattle in the field and a ridge of hills in the background. It is the lens designer who devises the optical combination which creates the image of the tree, the field, the cattle and the hills with such perfection of form and proportions of size that the whole image when collected on the film is a miniature of the actual scene, even more perfect, physically speaking, than the image formed in the human eye, because all of its component objects are brought together with an almost equal degree of sharpness which power the eyes do not possess. The image of such a scene as described above is formed by the lens not only In true rendition of form f size may be considered as an attribute of form) but also with all the glory of the infinite range of colors which is the other most important attribute of the scene itself and of any one object pertaining to the scene. The photographic film captures with marvelous fidelity the attribute form and has just recently, through Kodacolor, been able to capture the attribute color. The general effect that light has upon the film is the same for light of any color which is susceptible to bring about such effect. The emulsion spread upon the film undergoes a chemical change when acted upon by light, which chemical change results by processing in the formation of a silver deposit more or less dense in proportion to the amount of light that has produced the change. Colored rays which bring about such changes are called actinic rays. The degree of actinicity varies with the quality of the light, in other words with its color. Now, colored lights do not affect the photographic film to the same extent and in the same manner in which they affect the human eye. Red colors for instance are perfectly discernible by the eye. but have no influence 583