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PROBLEMS OF THE 16mm. PROCESSING LABORATORY
D. F. Cantlay, M.B.K.S.* Read to the B.K.S. Sub-Standard Film Division on January 29, 1947
THE war proved the value of 16mm. as an ideal training medium, and all three services demanded of the laboratories a very greatly increased output. Consequently, all available plant had to be converted to the mass production of positive prints by the reduction method, and production on original 16mm. negative or reversal had to be temporarily abandoned.
The enormous demand for release prints, always required in a hurry, led to the utilisation of every possible means of obtaining prints of reasonable quality. However, since the end of the war, the laboratories have been called upon to deal with a great deal more production directly on 16mm. film, and in an attempt to obtain the perfect sound print, a number of new methods have been worked out.
Alternative Methods of Producing 16mm. Prints
The position today is that 16mm. prints can be made in a bewildering number of ways. Fig. 1 shows the picture processes only. On the lefthand side, the direct 16mm. methods are shown, on the right, the methods using a 35mm. original.
The reversal method uses the original camera film for projection, the negative image normally obtained being reversed in the processing. This processing is normally carried out by the stock-manufacturers, and it is not proposed to consider it further here.
Reversal copies can be made by printing from the original, and again reversing, or by making a duplicate negative, and making prints in the usual way.
The second method is the direct negative-positive system, in which the ' positive print is made on a contact printer. A complication which arises at this point is that, should sound be required, optical left to right reversal of the image must be employed, since projectors are normally set to comply : with standards suitable for 16mm. sound prints from 35mm. originals, that is, emulsion to the lens. A print from a negative is projected emulsion to the lamp. The optical reversal brings the emulsion of the print to the lens, and the track into sharp focus. This is most necessary for the higher frequencies on 16mm. film.
A soft duping print can be made from an original negative, and from this, duplicate negatives are obtainable for release printing. A particular application of this process will be mentioned later.
Prints are made from 35mm. originals on a reduction printer, by several methods. The original negative or a duplicate negative will print a 16mm. . positive. A soft duping print may be made of the 35mm. original, and reduced to a 16mm. duplicate negative, from which prints can be made by contact printing. A soft duping print on 16mm. may be made from an original or a duplicate negative, and a 16mm. duplicate negative made by contact printing, final prints being taken from this 16mm. negative also by contact printing.
The Sound Track
Any of these methods may require sound, and Fig. 2 shows the various
♦Sydney Wake, Ltd.