Motography (Apr-Dec 1911)

228 MOTOGRAPHY Vol. VI, No. 5. too much time and become tiresome, having just the opposite effect on the audience. Mention many be made of the Kalem stickers for announcement slides for advertising coming films. ADVERTISING SLIDES. When advertising slides are mentioned an argument is immediately begun for and against the use of them. The revenue derived from them is about the only point in their favor, but everyone is looking for money, therefore the advertising slide. The advertising slide can only be used to advantage in the home theater and, if not too many are run, and they are of the correct nature, no objection will be made to them, and a little extra money can be pocketed by the exhibitor. No more than two or three should be run at each show. If more are shown the audience becomes impatient and the slides lose their intended purpose. One or two may be shown between reels thus making fewer ones at the beginning of the show. Advertisements requesting patrons to attend a certain restaurant or ice cream parlor after the show fits in nicely and are hardly regarded as advertising slides by the audience. Be very careful about advertising cafes of questionable character or winerooms in a home show. It may do you more harm than all the money you get from it. The same thing may be said of advertising slides as mentioned above in announcement slides. Make them unique and original and change them often otherwise they become a dead power. RUNNING SLIDES. The manner in which the slides are run is one of the greatest factors of their usefulness. The steropticon equipment must be first class to begin with and kept in good adjustment to produce best results. To get a sharp picture evenly illuminated all over the entire screen, the centers of the condenser and projection lenses should be in the same straight line. An excellent method for centering the lenses is given on page 175 of the October number under "Optics of the Projector," by Arthur S. Newman. When the center of the lenses is very much higher than the center of the screen a keystone picture results, that is a picture with the top wider than the bottom. This can be corrected by tilting the bottom of the screen forward. Another way to correct this is to make a mask or mat of sheet metal with the bottom wider than the top. This keystone mask should be fitted in front of the slide carrier. The slope of the sides will counteract the lines on the screen producing a picture whose sides form a perfect rectangle on the screen. This mask must be carefully made the slope of the sides having the same angle as those of the picture. Not the least in producing good results is the projection lens. In order to get a picture whose corners are not yellow a half size lens should be used for all lenses over ten inches equivalent focal length. Most city ordinces require that the slide carrier be made of metal instead of wood. Small knobs should be fastened to each side of the carrier, so that it may be pushed or pulled as the case may be, making it unnecessary for the operator to reach over the light to move the carrier. When removing the slide and dropping in a new one be careful that you do not shake the slide carrier causing the slide to jiggle on the screen. To obtain the best results in running slides you must have a dissolver. Passable results may be produced with various devices to cut off or dim the light while changing the slides, but the double lamp dissolver is the best. In the double dissolver the equipment of both lamps must be the same. Each lamp should have a separate rheostat so that the resistance in each line is the same, giving each lamp the same amount of current. The condensers should have the same focal length so that the circle of light will be the same at the projection lens opening, when both lamps are at the same distance from the lens. The lower lantern should be equipped with a double slide carrier, so that it may be used for running the slides alone in case the upper lantern becomes out of order. It is very necessary when dissolving that the outside lines of the pictures remain in the same straight line. This is impossible with the ordinary song slides as the mats on the slides are not always placed the same. For this reason each carrier should be provided with a mask or mat having an opening slightly smaller than that of the slide mat. These masks should be lined up carefully and secured to the carrier and better results will be obtained. The speed with which the dissolver lever should be operated depends very much on the slides. In changing views that are very dissimilar a quick movement of the lever is desirable, but where the scene changes but slightly the lever may be operated more slowly. Considering the general run of song slides it is better for the operator to work the dissolving lever faster than he usually does. In running slides with a single lantern it is not very pleasing to see a slide move sideways across the screen and another take its place. For this reason the light is generally cut off from the lens while the slide is being changed. If the "dowser" or light shutter is attached to the condenser mount it may be dropped in front of the condensers when changing slides. An ordinary round fan attached to the wall below the projection lens will serve to cut off the light while changing slides. Grasp the fan by the handle and flit it quickly across the lens, while moving the slide, The slip-slide carrier is sometimes used. In changing, one slide is pushed past the other one causing a blur on the screen. Eberhard Schneider has invented a double dissolver with two lenses giving the same effect as the regular dissolver, but requiring but one lamp-house. This is quite a saving as but one resistance device is required and by the arrangement of triangular glass prisms in back of the condenser, the light from the arc is split into two beams, one going through each lens. The various slides should be kept in a long box with compartments' furnished for the purpose. In this way an air space is around each slide giving it an opportunity to cool off. The danger of breakage is also reduced. In running the slides each one should be placed in the same position on the table so that they may be picked up and dropped in the carrier without looking at each one before dropping it in. This is especially necessary when running with a dissolver, as two scenes somewhat similar following each other a certain bit of landscape may jump from one side of the screen to the other. All of the slides should be cleaned each evening before the show by rubbing them off with wood alcohol using a clean rag. Care must be taken when changing the slides so that the slide is touched only on the border and not in the middle, as a finger print will surely be left on the slide. This is objectionable, to say the least. A moving picture machine has been installed at the Home for the Feeble Minded at Chippewa Falls, Wis. Once each week a number of reels will be taken to the home and an entertainment given for the inmates.