Movie Makers (Jan-Dec 1934)

323 A helpful review of some qualities of 16mm. cine films Filters and films accurately employed create rare beauty Rutherford from Ewingr Galloway Film characteristics CARL L. OSWALD ALTHOUGH a considerable amount has been written about the extent and diversity of cameras, lenses and L, accessories that are available to the amateur movie maker, not so much discussion has been given the various types of films. Perhaps we tend to take this all important tool of movie making rather for granted. Yet, since the variety of films now available to the amateur movie maker is wide in range, perhaps a rehearsal of their qualities will be helpful. At first, because of its overwhelming importance in amateur use, we will consider only reversal film — that is, film on which the positive image to be projected is produced on the same original film which was run through the camera. Parenthetically, it cannot be too strongly urged on all users of reversal film, regardless of what make or type it may be. to return it to the manufacturer for reversing, or processing. As an experiment, a movie maker might be tempted to try developing his reversal film as a negative, but while some films can be developed as a negative for subsequent printing, others cannot be so developed and one may waste his film in the attempt. On the other hand, the reversal process, as handled by the manufacturers, is so perfectly controlled and mechanized that the amateur cannot hope to equal the results obtained by them. In addition, such attempts are economically unwise, since the processing cost is included in the purchase price of the film. In short, so far as inherent photographic quality is concerned, the amateur need be responsible for the exposure only; the manufacturer can be trusted to do the rest. Reversal films fall into three general classes — panchromatic, orthochromatic and that which is color blind to red, green and yellow, the latter being in the slow speed positive or duplicating positive class. In the panchromatic class, the greatest advance in movie film to date, we have the regular speed and the superspeed, representing normal and about double normal speed, respectively. Normal speed is here taken to refer to the speed indicated on the average exposure guide, in which case the user of superspeed film is warned to admit less light to his film, usually by stopping down his lens from one to two stops smaller than that indicated by the guide. Panchromatic film, as the name indicates, is sensitive to and will record practically all the colors of the spectrum with the exception of a narrow band in the green. However, to get a black and white scale of color gradation truly representing the tones and gradations of the naturally colored scene, one must use a proper filter, the 3x yellow filter being the one generally advised for a scene made in white daylight. By selecting filters of other densities and colors, one is enabled to overcorrect, that is, to accentuate the effect of certain colors, to reduce the contrast between bright colors or to control the final screen result in other ways as required by the particular subject being photographed. For the comparatively new 8mm. camera, one film is supplied— a special fine grain panchromatic emulsion. The general technique in exposing this film differs in no way from that of 16mm. film and, because of its lower cost per unit of screen time, the new width is being adopted enthusiastically by new amateurs who do not need the screen image of much greater size and brilliance possible with 16mm. film, nor the advanced facilities available in many 16mm. cameras. Unquestionably. 16mm. offers the maximum in flexibility. The value of 8mm. lies in its compactness, lightness and economy. Orthochromatic film, lower in cost than panchromatic film. is generally sensitive to the spectrum only from the yellow green band down to the blue, the oranges and reds being beyond its recording range. Its speed is about the same as regular panchromatic film. The name, orthochromatic, meaning true color, is slightly misleading, for this type of emulsion was produced long before full color scale recording was thought possible and the type name given it at that time has persisted. However, its special meaning is well understood and should not be confusing. In the estimation of this writer, the particular value of orthochromatic film, aside from its lower cost and its remarkable freedom from grain, lies in its vellow green sensitivity which produces unusually harmonious results, especially in the yellow green light of late afternoon or in the grayish green light of a misty day. It is also very effective in photographing landscapes. In working with filters in conjunction with orthochromatic film, one should remember that the factors given with the filters usually refer to the number of times the exposure must be increased when panchromatic film is used. Hence, it is well to check with the maker as to the factor for orthochromatic film if that factor is not given. Gen [Continued on page 336]