Movie Makers (Jan-Dec 1931)

MOVIE MAKERS 373 "Pan" speeds ahead RUSSELL C. HOLSLAC New speed film vastly brightens the amateur prospect THE manifold advantages of panchromatic film have long been emphasized for the amateur. Moreover, he has come to realize, through his own experience as well as through technical information brought to his attention, that, on many important counts, panchromatic film has decided advantages for practically every shot, indoors or out. The richer, more natural screen results provided by panchromatic film on scenic shots are well known. This is because "pan" film is sensitive to many colors to which the ordinary or orthochromatic film is blind. For instance, red hardly registers on the ordinary film; it appears as black. And, since red or mixtures of this color usually are the tones that vitalize a scene, the blindness of ordinary film to them makes the scene seem flat. But panchromatic film is sensitive to red and to other colors as well and, when this sensitivity is further aided by the selective use of the proper filters, the screen results are notably better and more lifelike — they reproduce more nearly what the eye sees. The fine effects gained by professional cameramen are all made with panchromatic film. Now the amateur is -granted a new panchromatic film — one that act u a 1 1 y improves upon all the excellent qualities of the former "pan" stock and, in addition, brings to the 16mm. cinematographer tremendous new possibilities of its own. This new emulsion is the apotheosis of panchromatic, as it were, for it possesses characteristics of speed and latitude that were unknown before. Perhaps the ama gives perfect interiors teur's chief interest in its many startling qualities will lie in the fact that the new superspeed panchromatic film is fast. It is twice as fast as the ordinary "pan" film in daylight and from three to four times as fast when the subject is illuminated by artificial light such as that furnished by ordinary incandescent lamps. Its specific panchromatic characteristics are also very much improved so Without the unusual new superspeed light, pan that it will give, unassisted, monochrome color renditions that were formerly possible only with a filter. But, before passing to the practical avenues of application, let us investigate some of the fundamental technical advances that have been made in the new emulsion. Former film has been particularly sensitive to those wavelengths of light that produce in our eyes the sensation of the color blue. So great has been this sensitivity that any large area reflecting blue light (such as sky) has a tendency to become overexposed before the light reflected from other objects has affected the film; hence the glaring clear areas of sky seen with the "ortho" or ordinary film. This discrepancy may be evened up by using a yellow filter which holds back part of the blue but, since the use of the filter increases the exposure, this aid has not always been possible. Contrariwise, in the ordinary film, there was much less sensitivity to red and green so that the general result was likely to be more or less a falsification of color values. This was all the more apparent to the eye because, to it, red rather than blue is the more powerful color of the spectrum. The new film has been definitely made to produce results matching what the eye sees. Its sensitivity is greatest in the red region, increased in the green and lessened in the blue. It is easy to see how this will "even up" on exposure. It is now not necessary to dodge areas of blue because these do not affect this film in such disproportion. In effect, the new film is thus self filtering insofar as there is less necessity for a blue subtractive filter. At the same time, a greater variety of filter effects can be secured with the new film because of its added sensitivity to red. However, the special use of filters will not be discussed here extensively, as this subject merits detailed treatment. It is this added sensitivity to yellow and red that makes the new superspeed panchromatic so much more fast by artificial light, for the light given by the incandescent bulb is yellowish in tone and affects the new emulsion strongly. The well planned sensitivity curve of the new film operates to give it "latitude" which, in effect, means that there will be an improvement in the exposure of the shadows, or darker parts of the scene, as well as in the high lights. The film is also coated with a special backing material which effectively cuts down halation — the tendency of any sharp, brilliant point in the scene to [Continued on page 409] Eastman Kndak Co