Moving Picture World (July-Dec 1909)

n8 THE MOVING PICTURE WORLD THE ELEMENTS OF ACCURACY IN MOVING PICTURE MANUFACTURE. [ From "The Bioscope."] By Arthur S. Newman. The production of perfect pictures, "Steady Pictures" on the screen, is, or ought to be, the aim of every exhibitor. During the last three years a great improvement has taken place, but there is still much to be done before perfection in this particular is obtained. The exhibitor is almost wholly dependent upon the manufacturer, because, unless the film be perfect, no talent in exhibiting or quality in the projector can in any way improve matters. The operator may be provided with the most perfect machinery and appliances obtainable, his lighting arrangements may be faultless, but if the manufacturer of the film subject has not also produced perfect work the exhibition can only be second rate. The exhibitor being dependent on the manufacturer, it is natural his inclination will be to purchase from a source which may be trusted for steadiness, lie will, consequently, first look through the list of subjects of those producers whose pictures have the best reputation for accuracy in projection. The subject sells the picture in most cases, and no doubt a taking, or exciting, or well-staged film will sell well, even if unsteady, and will pass muster if run among a large proportion of steady ones. How much better would it be if all pictures, whatever the subject, were also steady — rock steady, I was going to say — but all pictures are steady, or said to be so, and we hear the same statement applied to nearly every projector on the market. The English seem to glory in vague terms, and the term steadiness as applied to bioscope matters is so elastic and so casually used that it now conveys little or no definite idea of what is to be expected. I have seen pictures described as "steady" when a side movement was present all the time, and this movement was as much as i-5oth of the width of the screen. Side movement is most easy to prevent, and in most cases may be cured by attention to the gate of the projector, though this is not always the case. Why cannot some definite measurement of deflection be considered the limiting point between steadiness and unsteadiness in a picture? Every manufacturer should have a testing machine, and all films in which deflection is greater than a definite amount should be rejected, and the defect in manufacture looked for and remedied as soon as found. I will endeavor to point out the reasons of unsteadiness, and indicate the means by which they may be remedied. The faults must in the first place be apportioned fairly between the exhibitor and the manufacturer. The exhibitor works by means of his projector, and if he provides himself with a good machine and keeps the same in good running order, his responsibility may be said to cease, and any fault remaining in his department belongs to the projector itself. This machine is at the wrong end for our purpose, as we must get to the root of the matter; so for the present we will leave the projector and the exhibitor and start at the beginning, dealing only with mechanical matters, and leaving the photographic or chemical side of the subject severely alone. After the film-stock has been coated with the sensitive emulsion, the mechanical problem starts; and the first difficulty is presented to us in the even coating of a film to an exact width. It is rare nowadays to find errors arising from uneven width of film; nevertheless, the manufacturer of film subjects should gauge every roll of film before use, and if found i-200th of an inch incorrect it should be rejected, because, if too wide, it may stick slightly in parsing through the gate of a well made projector or printing machine or perforator. If too narrow, in passing through the projector, a slight swerve fnun side to side will lay the foundation of inaccuracies, it will be aggravated as to various later processes, and proceeded with. The method by which exact gauge can be verified most easily is to have two width gauges, one -to be t-_|COth of an inch larger than the exact width, and the other t-_|00th of an inch smaller. The correct film will then pass easily through the larger one, and be tight in the smaller one. The next process is the perforation of the film, and here the mechanician's skill is taxed to its greatest extent. Perforation is the most important and difficult of all the operations, and the utmost care should be taken to ensure its absolute correctness. Without correct perforation, steadiness must suffer, and no after treatment can reduce in the smallest degree errors introduced at this stasie. A perfectly perforated film should have the holes cleanly cut. the lines of holes should be at corresponding distances from the edges, and should be of the correct distance from one another, both across the film and in the direction of its length. The size of the hole and its shape vary somewhat in different samples. and are not "per se" of importance: those originally adopted by Messrs. Pathe seem now to be the general favorite. The distance apart of the holes in the film measured in the direction of its length is generally called "gauge." From an engineering point of view, the word "pitch" would much better describe its measurement. The gauge, or pitch, of a film is generally agreed to contain sixty-four holes in one loot. i.e.. measurement from the center of the one hole to the the center of the sixty-lith hole, or from edge of one hole to the corresponding edge of the sixty-fifth hole. If this measurement is complied with, most people are satisfied; it is, however, only one of the requirements for the exact measurement, it being quite possible to fulfil this condition and still have a very imperfectly perforated film. It is of much greater importance that all succeeding holes on one side of the film should be exactly opposite those on the other side, in which case the precise distance taken up by sixty-four hides and spaces is not so very important. The variation of t-500th of an inch in the foot of either side of the standard is not of any great importance, the particular point is that the perforation should be evenly distanced. The exact gauge, or pitch, is only important where a continuous or rotary printer is employed, when to obtain absolute accuracy in the printing operation, it would be necessary to have the positive film perforated to suit the developed negative from which the print is to be taken. In order to do this the negative film will require to be of a long gauge, to allow of shrinkage in development, or the positive film could be perforated to a gauge somewhat shorter than the normal, the amount of difference being determined by the amount of shrinkage to which the special sample of film-stock used is liable during the development and drying. When in use the perforator must be kept scrupulously clean and well oiled; all old or dirty oil being wiped from the working parts each morning before starting. The gauge, or the pitch, of perforation must be verified from time to time to make certain that all is proceeding rightly, and the speed of the machine and the temperature of the room kept as even as possible. PICTURE FILMS. A patent has been taken out for an invention which renders it possible to carry out the development of moving picture films in the form of daylight-loading spools by daylight or by any actinic .light, without the employment of a separate dark chamber for transferring the exposed film to the developing reel or flexible apron. A metal chamber of a cylindrical shape, with closed ends which are fitted with small holes for the inlet and outlet of air and liquid, the holes being trapped so as to prevent the entry of light, i;5 provided with a lateral opening which can be covered light-tight by a hinged door, which has an aperture which can be covered when required by a spool box adapted to receive the spool of exposed film to be treated. This spool box is adapted to slide over or otherwise cover the aperture in the hinged door, so as to exclude the light. Within the chamber is a flanged reel with spindle which can be rotated from the outside of the chamber. The film is wound on a flexible apron with thickened edges of rubber or other suitable material having longitudinal ribs, the apron itself being made preferably of celluloid; the thickened edges are by preference attached to the apron by stitching along the depressed center of each thickened edge. The apron can at one end be clipped or otherwise attached to the reel spindle and coiled round it together witli the film. The thickened edges of the apron keep the sensitive surface of the film from contact with itself and with the supporting apron as is well-known. Within the chamber is an inner portion of a wall bent to the curve of the outer wall, and between the two there is a space; this inner wall extends from end to end of the chamber, and in conjunction with the ends of the chamber forms a light trap: the space between the two walls also forming an aperture for the passage of the flexible apron. The O. M. Edwards Company, of Syracuse, X. Y., are placing upon the market a film cabinet at a moderat price. This cabinet is built to pass the examination of the Board of Underwriters. It is made of rolled pickled steel, thoroughly baked and finished in olive green, with a decorative gold strip. It contains six shelves and has the capacity of holding 50 reels. Some features are introduced not heretofore attempted in any similar cabinet, viz.: the door has a spring attachment closing it automatically and thus avoiding any possibility of it remaining open through the carelessness of an employee. The locking device consists of the latest arrangement in lock design, having a bolt at the top. bottom and side of door, all being operated by one knob on the outside, each bolt bedding the door tightly closed by an independent spring pressure.