The motion picture projectionist (Oct 1928-Oct 1929)

26 The Motion Picture Projectionist October, 1928 46 Just Like Its Dad'9 / AND NOW! The STRONG ELECTRIC COMPANY begs to announce the arrival of the STRONG Junior Reflector Arc Lamp For use in small theatres, schools, and elsewhere now using Incandescent equipment or where finances are a factor, but where de luxe projection of the famed Strong quality is desired. You Can't go wrong with a Strong The STRONG ELECTRIC COMPANY Also Makers of Strong Rectifiers 2501 Lagrange Street Toledo, Ohio I E ■ BMW s VS i T 8 H PATAPtO FOB0 F0 SAFETY SHUTTER t r"""",i,"t i STOP Z5£ FIRE YOU CAN DO IT WITH A "BEST" SAFETY SHUTTER Positive Trip Lever Drops Shutter When Film Breaks at Intermittent PRICE $10.50 BEST DEVICES CO. Film Bldg. Cleveland, O. New Dworsky Cleaner for Theatres For a long time there has been on the market a motion picture film cleaner, made by the Dworsky Film Machine Corporation, now of Long Island City, designed to rid film of the dirt and gritty substances which attached themselves to the film. The Dworsky Film Machine Corporation has hitherto manufactured a cleaner for use in the exchanges only. But no,, it has brought out a junior model for theatre work. It is small and compaci and will fit unobtrusively into the smallest projection room. It is a power driven machine and almost self-operating. It requires no unusual supervision, as the mechanism is so simply devised that there is no chance of the film being caught, snapped off or otherwise damaged as it passes from reel to reel. The film runs through a specially prepared film cleaning fluid which is also sold by the Dworsky Company, called Filmex. It is claimed that this fluid washes the film thoroughly without injuring the emulsion. A reel of film can be cleaned by this process in five minutes. The Dworsky machine is beginning to be widely used in sound recording studios and exchanges handling sound film, and it is especially recommended for theatres playing sound pictures. 62 1/2 % Less Heat on the Film {Continued from page 21) resulting in an increase in illumination of the projected ima^e of about 15%. In view of the foregoing it is interesting to note that we are able to proportion the blades of the new type shutter so that we have a period of darkness representing that time during which no light reaches the screen of only 45 percent with the new shutter and a period of light of 55 percent in contrast with the old type of disc shutter, in which we have a period of darkness of 60 percent and a period of light of 40 percent. Eliminating the Heat The action of the new shutter in eliminating the heat from the film is due naturally to the interception of the light beam and, incidentally, the heat between the light source and the film. As the shutter makes one complete revolution during the cut-off action and another complete revolution during what might be termed th; flicker interception, it will be readily seen that the entire action of the light beam and its incident heat is prevented from acting on the film while the film is in motion before the aperture and once while the film is at rest before the aperture. The heat of the light beam being allowed to reach the film only at two short intervals, once when the film comes to a stop before the aperture and again after the flicker interception and until the film starts in motion again. Some interesting data was secured as a result of tests conducted in our factory, in