International projectionist (Jan-Dec 1935)

20 INTERNATIONAL PROJECTIONIST April 1935 Proper Screen Selection IT IS not my purpose to discuss the comparative merits of Suprex and low-intensity projection but rather to point out the results obtained with the white, beaded and silver screens when used in conjunction with either light source. From the standpoint of its ability to reflect the incident light satisfactorily to all parts of the theatre, the white screen is the most efficient. However, in order to have proper screen illumination, it is necessary to have a powerful light source such as high-intensity (old style) ; hi-low, or the new A. C. or D. C. Suprex arc. The quality and quantity of the light obtainable from the latter type arcs may vary, but with either arc it is sufficient to justify the selection of a white screen. Here we approach the ideal — satisfactory screen brightness from all seats. But — there is the proverbial fly in the ointment. A large majority of theatres are now equipped for low-intensity operation, and many such houses are using white screens that have outlived their usefulness. Decidedly inferior screen illumination results, and this is the one thing that no exhibitor, no matter what his financial position, can afford. The remedy for this condition lies in either one of two courses. First, a com Alliance Sues to Recover Local 110 Funds Sensational charges of misappropriation of Local 110 funds by the late Thomas E. Maloy and his brother officers were contained in a suit filed in Chicago Circuit Court by the International Alliance. Maloy was killed by gunmen on February 4, and all his lieutenants have since been removed from office by the parent body. Named in the suit are Effie P. Maloy, widow of the slain union leader and administratrix of his estate, and eleven former officials of Local 110. An accounting of the union's funds is asked, the bill stating that examination of the books disclosed that they "have not been properly kept and balanced." More than $400,000 came into the hands of the defendants for which no accounting was made, it is charged, which amount was "misapplied and converted by said defendants ... to their own use or to the use of some of them." J. C. Heck DA-LITE SCREEN COMPANY plete change from present L. I. equipment to the Suprex arc by means of either new equipment or conversion of existing equipment. This change would in either case also call for a new white screen. The second course is to continue using the present L. I. arc and replacing the white screen (if one is now being used) with a silver or beaded screen. In all narrow and medium-sized theatres this combination will not only assure vastly improved screen results but will also cost much less. Certainly no one in the projection field is content with poor screen results, and least of all an equipment manufacturer. One must not lose sight of the fact, however, that first cost and maintenance costs are vital factors in any exhibitor's budget. There has been some objection voiced to the allegedly slightly yellow color of the L. I. arc light, to which there was no objection prior to the advent of the Suprex arc. From a boxoffice standpoint this advantage seems to be unduly stressed. The so-called "harshness" of the beaded and the silver screen is caused by too much light when used with either a straight H. I. or the Suprex arc. This condition does not hold true where the L. I. arc is used. Confronted with such a problem, the exhibitor will want to assemble all the facts and check the relative merits of arcs, screens, etc., in relation to his own individual requirements. Generally speaking, I should recommend the use of a white screen with all H. I. and Suprex arc installations. Where a L. I. arc is being used, a beaded or a silver screen will give splendid results in all the narrow or medium-size theatres. Generators, Rectifiers and Bulbs A leading manufacturer of generators, with long experience in the motion picture projection field, comments on several important aspects of arc power supply. John Hertner Probate records state that Maloy left an estate of $2,000, exclusive of insurance which, under a double-indemnity clause applying to the character of Maloy's death, is said to total $100,000. Editor, International Projectionist. SIR: I was very much interested in your very complete answer to Mr. Hoffman's contention as to the superiority of the A. C. arc, as set forth in your last issue. There are a few minor points, however, which deserve some notice. Mr. Hoffman states: "In addition there is approximately a 50 per cent increase in power consumption when motor generators are used in an overloaded condition, which means decreasing generator life and upping current consumption from 7 to 9 K. W. depending upon the efficiency of the set." He had previously spoken of the 30ampere L. I. arc consuming 5 K. W. from the line. The best information that we have available is that instead of 5 K. W. it is actually between 3.5 and 4 K. W. where the generator produces 30 amperes at 80 volts. Now, turning to the above quotation, and being somewhat familiar with generators, not only our own, but other makes, I believe I can vouch for the fact that, in general, the generator designed to produce 30 amperes for a L. I. lamp will produce 45 at about the same efficiency. I have before me a test on a 30-60 Transverter which is probably not far different from other makes of generators. It shows an overall efficiency of 70 at 30 amperes, 71 at 45 amperes, and 69 at THE HERTNER ELECTRIC COMPANY 60 amperes. It is capable of continuous operation at 45 amperes. You will note, incidentally, that when delivering 30 amperes at 80 volts, the K. W. line consumption is 3.43 and not 5 K. W. ; and that at 45 amperes the line consumption would be 5.1 K. W. and not 7 to 9 K. W. Now, coming to Mr. Brenkert's article in the same issue1. He mentions the life of tubes. The writer has mingled considerably with supply men, theatre owners, and projectionists, and his conclusion is that tube life seems a matter of luck. Recently in an Eastern city a theatre owner was met who was extremely riled on tube expense. The local supply man confided that tubes were the bane of his life because he either made gratis replacements — or made enemies. In some districts the troubles do not appear to be serious and the rectifier is making more headway. As to the copper-oxide rectifier: while its efficiency is lower than that of the bulbs, being 65 per cent when fan losses, etc., are included, there is a chance that the units will have a considerable life. This, of course, remains to be proven. Of course, all rectifiers transmit line disturbances to the screen, not having the benefit of the fly-wheel action of the revolving parts of the generator set which will carry the load across a period of low or zero A. C. voltage. 1"A Manufacturer's Views on L. I. Lamp Conversion," p. 18.