Motion Picture News (Sept-Oct 1918)

1898 Motion Picture News ^er^Tiv^j Projection^ ul jue stiorts Arts were cU Remote Focus Control EMIL A. NELSON, owner and manager of the Star theatre, Duluth, Minn., sends us specifications of two United States patents which have been recently granted him on devices for focussing the projected motion picture from a place remote from the lens of the projector, as, for instance, from the front or rear of the auditorium, or from any other desired location, depending upon the arrangement of the electrical circuit from which the device is operated. Mr. Nelson shows several variations in the mechanical principle of the device in his patents, and he states that the same may be adapted to the focussing arrangements of both the Power and Simplex mechanisms. We proceed to briefly describe the two principal types of Mr. Nelson's device, which permits the screen picture to be focussed from various parts of a theatre by pressing a push button located in any desired place. Fig. 2 Fig. 1 shows the simplest form of the device, which consists of a small motor, capable of running backwards and forwards by closing suitably wired circuits. As the figure shows, the motor is connected by suitable gearing to the rotating jacket by which the projector lens is usually focussed, the ratio of the gearing being such that the jacket is rotated very slowly by the motor. It is readily seen that if the motor is properly connected into a circuit which extends to various positions remote from the operating room, and at which positions push buttons for closing the circuit are located, the definition of the screen picture may be regulated from the auditorium by pushing the proper button until the screen result appears correctly defined. Fig. 2 shows another apparatus devised by Mr. Nelson for accomplishing the same end. In Fig. 2 two solenoids designated by 11 and 12, are provided with the cores 15, whose stroke may be regulated by the adjustable washers 18. As is apparent from the figure, the cores of the solenoids bear against the teeth of the gear 7 {mounted to the focussing jacket of the objective), so that when the solenoids are respectively excited, the gear 7 will be slightly rotated causing the focus of the objective to be altered. The wiring of the circuit operating .the device is simple, and extends to various parts of the theatre, as in the previous case, thus the results achieved by either device would be substantially the same. Apparently Mr. Nelson has not yet undertaken the manufacture of these remote focussing controls, and they are not as yet upon the market; consequently we can not comment upon the performance of the same in actual use. Many cases can be conceived of, however, where a system of controlling the focus in this manner would undoubtedly prove valuable in maintaining critical screen definition, provided, of course, that those who manipulated the buttons were competent judges of definition. More About Carbons Mr. T. A. Gramtling, Florence, Ala., writes as follows : " This is my first offense and it will do some of the boys some good, especially Mr. Fallon of Sioux City. If I understand rightly, he lays all his arc trouble to carbons. Now, a few years ago I would have sided with him, but since the Big Show on the other side of the pond opened up the American carbon manufacturers woke up to the fact that just as good, if not better, carbons could be made in the good old U. S. A. as in Europe. They are more than making good, as both National and Speer are turning out a superior grade of carbon to any imported brand I have ever used, and believe me, I have used some few different brands, from street arc carbons to French metal cored. But to get back to " Sioux City " and his trouble, and every other trouble of a similar kind, dear brothers of the profession, don't put the blame on the carbons altogether; use a little common sense and a whole lot of judgment, and a little study and experimenting mO help some, too, in your selection of sizes of carbons. I have always found that with the G. E. motor-generator set using 25 to 50 amp. across the arc you get from 42 to 48 volts, and the best possible results are obtained by using a cored upper and a 5/16" Silvertip negative, keeping the carbons from 54" to W apart. Set with the negative forward so that point will split the core of the positive. If Mr. Fallon will try this I think he will get rid of his trouble; also, if he will burn enough carbons for a day's run long enough to form craters upon them he will find a big improvement in results after a new7 trim. Well, friend Editor, this may or may not be information that's new, and I am only giving you this from my own experience. I am always willing to learn and the Projection Departments of both the News and World are the best schools I know of, and take it from me, when I can't buy both I look up some one that has them." Comment: Due, perhaps, to his having missed some of Mr. Fallon's earlier communications, the present correspondent has not interpreted quite rightly that gentleman's present viewpoint in the matter of carbons. About the first of this year Mr. Fallon had unlimited trouble with a certain lot of apparently defective carbons, and carbons have remained more or less a pet antipathy with him ever since, but he long ago surmounted his carbon difficulties, according to his recent letter, and as we know Mr. Fallon to be a broad-minded student of projection, we feel sure that he never intended to convey the impression that " the carbons are always to blame." Our correspondent raises a point which should not be lost sight of when he praises the American manufacturers of projector carbons, for some of the improved varieties which they have placed at the service of projectionists, represent real advances in