The motion picture projectionist (Nov 1931-Jan 1933)

18 Motion Picture Projectionist March, 1932 Fig. 3. Projector Opened for Use ing the roller, 11. If the pressure on this lever is released, the roller 11 returns into contact with the drum, and the loop formed by the film is taken up by the movement of the drum. The importance of the formation of this loop is that in this operation the film advances by one perforation. Masking is thus effected by the displacement of the image by an amount equal to a quarter of its height. Motor Drive and Lighting The driving parts are carried on a fixed aluminum platform and can be removed as one unit from the box. This block consists of an electric motor , 12; a pulley drive, 13, reversible for rewinding; and a transformer, 14, to feed the lamp 15. In front of this assembly, against one of the panels of the box, are mounted side by side two rheostats, for the lamp and for the motor, with finger controls, 16 and 17, for their adjustment; and an ammeter, 19, for the control of the lighting system. A plug let into the casing provides for the connection of the apparatus to a source of electric power. The lamp used is a 225-watt Phillips, taking 30 amperes, at 7% volts. The beam is of about 525 cp. in a horizontal direction perpendicular to the tungsten filament. The lamp is conical in shape and works upside down in order to avoid the blackening of the bulb around the filament. The lamp is suitably supported and adjusted. The optical system includes a two-lens condenser 25, and spherical mirror 26 in line with the axis of the filament. As a safety device there is a wire gauze, 27, which is arranged to come into place automatically between the light source and the condenser when the film is stationary. This takes place by a centrifugal action. Its effect is to protect the film from any dangerous degree of heating without restricting the light unduly when the machine is used for still projection from selected pictures. Procedure for Focusing As regards focusing, the apparatus possesses five collimating lenses C (Fig. 1), arranged on a rotatable disk, and by means of these the image can be focused on a screen at any distance from 6 to 32 feet. The milled edge of this disk projects through the casing at the side so that it can be rotated by the finger, and a spring Fig. 4. Internal Arrangement detent sets it in accurately centered position whichever lens is in action. A rectangular window in the front wall of the apparatus, made to allow the beam to pass, is fitted with two sliding covers adjustable vertically to cut off parasitic images which would otherwise be thrown on the screen. Rewinding at the end of the projection is very simply carried out. The film is released from the drum and from the guiding sprockets. An adjustment is then made, to allow the take-up reel to turn freely on its axis and to fix the feed-reel to its axis. The full take-up reel thus becomes the feed-reel, and vice versa. The motor, running just as in projection, then rapidly rewinds the film, leaving it ready to project again. The Film Mutilation Problem A Letter from Mr. Carlson on the Subject Editor, Motion Picture Projectionist: Sir: Regarding the matter of Film Mtitilation, which . you are covering with a series of articles in your magazine, wish to make a few remarks: Most of your articles seem to be concerned more with the damage to new prints, such as processing to prevent emulsion deposit in projecting, proper tension on projectors, etc., but there is one phase of the whole matter which it seems is being overlooked, perhaps because it is not considered of enough importance, but if looked into carefully am convinced from my own experiences and observation as a projectionist, will warrant considerable inquiry and discussion. Most of the film exchanges here in Los Angeles seem to feel that most of the damage to film is caused by improperly adjusted projection equipment, which no doubt is true to a certain extent, especially too much take-up tension while the first reel in each machine is run at the beginning of daily run, which can be over come by anchoring an empty reel in the lower magazine while warming up the machine and thus save the first several hundred feet of the first reel of the day's run from having to perform this duty. Notice the leader and front end of most features and notice patches, etc., if the print has been used for any length of time. The succeeding reels of a feature are in much better shape than the first and third in practically every feature the writer has built up (most of the film run in the theatre where the writer operates has been used for considerable time). All of the above, while having considerable bearing on the matter of film mutilation, is of relatively less importance on the matter than is the damage to film caused in handling, transporting, shipping, etc. In tearing down shows, if the film is wound smoothly and evenly with no overlapping edges very little damage will result from kicking the containers around like footballs, which is the treatment it receives at the hands of delivery men (believe it or not), but what will happen, I ask you, if your projectionist in his hurry to tear down the show uses a hand rewind and does not guide the film so it will wind smoothly on the reels? The containers are then slam-banged around on their merry way back to the exchange, and if the container happens to be one of the variety in which the reels lie on their sides, can you imagine what happens to the film? There is one exchange here in Los Angeles which uses practically no other kind of a can but this lay-flat type and their film on all prints which have been used for any length of time at all is in a deplorable condition. Recently ran a feature which less than two months before had its first run in the city, in which I counted sixty-five patches in the first two hundred feet of one of its reels. For the past year have paid particular attention to the type of can in which the film was received and unless the film was practically new it was in far worse shape when received in layflat cans than when received in onedge cans. — Charles G. Carlson, Los Angeles, Cal.