Moving Picture World (Jan-Jun 1910)

512 THE MOVING PICTURE WORLD OPERATORS' COLUMN. QUESTIONS AND ANSWERS. Conducted by F. H. Richardson. Let me impress upon writers that they must be very careful to send complete data when asking questions. Better tell too much than not enough. Give make and model of machine, size of picture, kind of screen. Length of throw, size of connecting wires, etc., etc. To illustrate: A few days since the question was asked. "What can I do to prevent my condensers breaking?" Not a word as to kind of condenser mount or lamp-house, fans in operating room, open window behind machine, etc., etc. I could make no intelligent answer. Make your data complete and 1 will try to help you. * * * A Hard One. — Manager, in Iowa, writes as follows: Am using, in one of our theaters, a machine, and every picture thrown on the screen is blurred. That is to say, the blur occur when objects are in motion. For example, in the film. "The Last Deal," a Biograph, when the card game is on. the picture is clear and sharp — in fact, all that could be asked in a first-class projected picture. But as soon as anyone, or any object, moves about, or moves in any way, that especial object immediately becomes blurred. This does not occur at the sides or center, as would be the case were the film bulging over the aperture, but all over the entire screen. Still I do think the film does bulge and have done everything under the sun to remedy the defect, but can't seem to overcome it. My pictures are so clear otherwise that very few have commented on it, probably thinking it should be so. But I know it should not, and it has worried me nearly sick. Hoping you will be able to give me information enabling me to overcome the fault, I am, sincerely. . This letter is so interesting that I print it in full, inviting any of my readers who may have had similar experience, if any there be, to send in a solution. Frankly, it has made me take to the tall timber. I cannot even imagine anything that would produce any such weird effect as this. If the figures are perfectly clear while still, they should also be while moving. There might be some figures blurred by reason of too rapid motion, but, as I understand it, all moving objects are blurred in this case, and it occurs, not in some films, but all the time. T present it to our readers as a case so queer as to be wellnigh a curiosity. Sorry to say I cannot even make an intelligent guess as to its cause, therefore know no remedy. * * * Film Jumps. Shadows. — Charles Town, W. Va., says his film jumps once in a while and there are occasional dark shadows just the same as when the shutter is out of time. Asks reason. From your description I would say that the film jumps when a bad patch goes through, or there is some other fault in the film itself. The trouble is, I am quite sure, in the film itself and not in the machine. As to the shadows: The shutter being out of time does not cause dark shadows, but does cause a "travel ghost," the same being flashes of white up or down from any white object, particularly from letters in a title. The same effect is had, much exaggerated, when the shutter is removed entirely. No, the trouble is not in the condenser lenses. I shall have to have a more minute description of the "dark shadow" effect to answer you definitely. For one thing, note if these shadows appear only when you run at low speed. I await further information. * * # A Bunch of Questions. — Roxbury. Mass.. writes: (i) Would like to know cause of picture being out of focus on each change of scene. (2) Why do carbons get red-hot when all connections are tight? (3) What size condenser lenses should T have for a t6 x iq picture at 78 feet, alternating current?1 Xow using one 6lA and one "jl/i, but they crack frequently, (4) Have Power's rheostat, and after checking three coils connected in multiple with a non-adjustable it shows no increase in light. The fourth coil increases the light, but can't hold it there as it heats up. (5) Have a Mullen coil which was used on uo-volt, 60-cycle current. Current has been changed to 60-cyclc and now coil heats up. "What is cause and is any change in coil necessary ? (6) What causes top of picture to cut off on a slant while bottom is level? (7) Am drawing only 40 amperes, yet blow 60-ampere fuses almost every day. What is cause? (8) What causes light to Form similar to a figure eight at times? (()) Would like to know how to make the thing which takes the place of the hand in front of hood in changing slides. It is made of film cut in a certain way and thickness and placed in a brass piece. ( 1 ) From what you say in another portion of your letter jour screen is placed in a different position in setting the stage. Tins might affect your picture focus if the movement be very much. Sometimes different scenes in a film will require different focusing owing to some technical peculiarity in photographing, but an unsharp positive cannot be corrected in the projecting machine. (2) I take it you mean that the carbons get red-hot at contact with carbon arms. This is because the carbon is not making good contact with the metal. Clean out inside of arms with a file, dressing them up, if necessary, until good contact is had with carbon entire width of the arm. (3) You are using a 4-inch projection lens, and two 7l/t-inch condenser lenses will just suit that length of projection lens. (4) Don't understand! Send in sketch of your connections. (5) Xo change should be necessary unless the voltage has been increased. If so, the coil would be too small. Perhaps it has deteriorated through age. (6) May be that light is striking top of lens hole in wall of operating room. That is most likely explanation. (7) If you really are drawing but 40 amperes, it is likely you have a ground, and a heavy one at that, somewhere. (8) I think you must mean the light at the spot. It is caused by arc being too long. (9) You are too many for me, old man. Never saw the device you name. Think you must have seen something made from colored gelatine paper. A sort of colored shutter. You are at liberty to send in all the questions you may wish — that is what the department is for — but be very careful to make them perfectly plain so that I may understand what you are driving at. It puzzled me considerably to make out what you had in mind in some of those submitted this time, and one (No. 4) I could make nothing of at all. * * * Stereopticon. — Indianapolis, Ind., asks how much current should be used on a dissolver lamp. Also whether or no the lamp-houses could not just as well be set side by side as one on top of the other. The amount of current you should use will depend on circumstances. With alternating, more should be used than with direct current. The more current you use, the brighter will be your picture, of course; but, on the other hand, there is greater liability of slide breakage with strong light. With direct current. 18 amperes is enough for the stereo, unless the picture be a very large one, when it may be increased to 25. Eighteen amperes D. C. gives a soft, beautiful projection and a picture which is by many preferred to the brighter one. When running travelogue slides, which must remain in the light for some length of time, never use more than 18 amperes. Stereopticons should have an adjustable rheostat with a range from 15 to 25 amperes. Then by cutting down the current when the chorus slide of a song comes on, it will not be broken; also you may reduce current whenever you have a very slow song or travelogue slides. The lamp-houses may be set side by side, but it would be a very unhandy and impracticable arrangement for the operator, since he would then be obliged to reach clear over the nearer lamp-house to change the slides in the other, or to trim his lamp. There would be no difference at all in the result on the screen. * * * Lens, Screen, Lights. — Mt. Clemens. Mich., asks: (1) If Darlot lens is the best make? (2) If machine being 15 feet above center of screen. 65-foot throw, will affect picture to an>' extent as regards its uniformity of size, and, if so, what is remedy" What size picture gives best results at 65 feet? What color lights to use in auditorium when picture is on, and whether or no there is any law to prevent a manager enforcing a house rule requiring ladies to remove their headgear? The Darlot lens is a most excellent article, but for obvious reasons it is not the office of this department to compare rent makes of lenses, machines or other goods. Darlot lenses are imported from France and kept in stock by all leading supplv houses. The Gundlach-Manhattan Company, of Rochester. N. Y.. make an excellent projection lens. (2) The machine being 15 feet above screen will, of course, have a tendencv to make the picture a trifle wider at the base. At 63 feet I think there would be very little distortion— not enough to be easily discernible. The remedy is to tilt the screen to face the lens sauarely. If your picture is in focus all over the screen. I think, in your case, this need not be done. Fairly good pictures are often projected at an angle oi as much as 25 degrees: in a few cases even more. Speciallv ground lenses may be had for this purpose, but they are expensive and not desirable except in extreme cases. 'Size of picture, at 65 feet or any other distance,