International Review of Educational Cinematography (Jan-Dec 1932)

236 — Preservation and Regeneration of Films. For a long time technicians have been studying this question for it is of the greatest practical interest and its solution would certainly bring about a great economy by lengthening the life of films. In certain countries, chiefly in Germany and America, the regeneration of films is accomplished on quite a large scale and by various methods. These methods are of three kinds depending upon how the liquid compositions employed act on the surfaces of the film : first, processes consisting of a simple varnishing of one or both surfaces ; second, processes such as Recono, in which both surfaces are subjected to a real fusion (this after polishing does away with scratches, etc.); third, absorbtion processes, in which the composition employed is applied only to the emulsion surface of the film. In this last category we have the ' SmaltoChromo-Film ' process, recently invented by an Italian, M. Ottorino Tedeschini, which seems to give really satisfactory results. This consists of a chemical composition which has the property of preserving positives from scratches resulting from repeated projection, above all on the emulsion service. This composition is not a varnish with a lacquer, resin or nitro-cellulose base which rende film brittle and liable to break, but a chemical which is entirely absorbed by the emulsion base itself. It renders the latter more flexible and supple so that when the film passes through the steel rollers it does not lose particles of gelatine which by accumulation cause scratches, etc. and thus ruin projection. In the sound film it also eliminates parasitical noises caused by deterioration of the sound track. This " Smalto " also strengthens the joins and avoids laceration of the perforations. In thus reducing the friction between film and roller, sprocket lubrication is less fre quently required and oil, well known to harm the film by deteriorating the emulsion, is less likely to get into the film track. Oil and dust together form a coating on the film which obscures the image and impairs the clarity of the sound reproduction. Additionally, oily gelatine tends to melt under the heat of the illuminant and it then begins to peel off from the celluloid et film treated with " Smalto-Chromo-Film " also gains in transparency thus the image is more perfect and the sound more clearly reproduced. This applies to new positives. The Tedeschini Process also really regenerates old films. It cleans away grease and the oily coating which eventually covers both sides of the film and gives back to it its original flexibility. What is more important it does away with all but the most serious of scratches. Finally the Tedeschini Process preserves film from heat and damp and it is therefore useful for the treatment of negatives which it preserves from deterioration caused by the action of hyposulphites and other chemical impurities absorbed by the gelatine. " Smalto-Chromo-Film " is applied to the emulsion after printing by means of a special machine. An optically compensated portable projector, the " Simplicine-Gaumont ". The special advantagesof optically compensated projectors are well known. Amongst these must be counted, that of the simplicity of the mechanical organs (but not that of the polical organs) ; that of a more regular film traction due to a total absence of jerks ; that of less deterioration of the perforations, that of a greater luminosity in certain cases, and finally owing to the elimination of the shutter, a great degree of silence in operation. These advantages are due to the essential fact that the film traction is continuous and they are often cancelled out by the complication of the optical system and by the difficulty