Moving Picture World (Jan-Feb 1927)

PKetter Projection yiiis Department Idas founded, in 1910 bi{ its Present 6ditor~ $ J-f. Richardson Better Projection Pays Varying Focus Worries Early EA. EARLY, projectionist, Lincoln Theatre, Parkersburg, W. Va., says • we gave him excellent advice concerning a screen for one of the theatres last summer, but now he is in trouble about another. Has two “low intensity lamps,” (by which he means reflector type lamps), an 80 foot projection distance, a 16 foot picture, Gundlach V/2 E. F. projection lenses. Lamp has regular Powerlite equipment. Has quite an angle, presumably up and down, and has set the screen at about 25 degrees. Screen prefectly white when reflecting light without film. When film is projected some scenes are wonderful. Just great! Others are out of focus. Closeups are sharp. Long shots are not good. As a rule titles are not sharp. Focus them in one place and not in another. Stopping Down Lens Fails Has tried stopping down lens. No good. On dark scenes there is a very pronounced carbon or mirror-center image at bottom of' picture. Screen is a highly reflective one and he believes the image of the carbon and holder on screen, and on certain scenes is registered, thus causing the image spot at bottom; also the out-of-focus effect he gets on some scenes and on titles. Says he has been told the fade-away is causing the effect. It seems that this editor just reaps trouble. No sooner do I get one tough thing cleared up than some one hurls another at my head. I can answer nearly anything, I sometimes think, but darn it all, I’m no wizard. I don’t know what causes the effect, but I do know it is NOT the screen, or at least if it is I am unaware of anything which would cause a screen highly reflective or otherwise, to pull a stunt like that. Focussing Not Likely I don’t think it is at all possible for the carbon, the crater or the carbon holder to be focused at the screen, no matter what the condition. The focusing of these objects at the screen on some scenes and not on others would NOT affect the focusing of the scene itself, because that depends entirely upon the quality of the projection lens and the points of equivalent focus. If the projection lens is itself perfect, and in perfect condition (as it must be if some scenes are in sharp focus) and the film lies at all times flat over the aperture, then there seems to be no reason why whatever the condition of focus is on one scene should not be the condition on all other scenes, provided they are themselves of equal sharp photographic focus. If you merely said the out-of-focus effect occurred occasionally and intermittently, I would say examine the projection lens and see that all its elements are held tightly in Bluebook School This question is submitted by a Philadelphia projectionist who uses only his initials — R. G. B.: If you were employed as projectionist in a theatre under construction, in which pictures and prologues, or pictures and tableau are to be used, and you were asked to submit a tentative list of the equipment required in the projection room, what would you ask for, the current to be 110-120, with a 3-wire projection room service circuit? The room itself will be 18 feet wide by 9 deep, located at front of balcony. Projection distance is 70 feet. Picture 18 feet wide. Distance screen to rear seats 130 feet. Auditorium 82 feet wide. Screen to front row of seats 25 feet. This question is very well put. All the various items have a meaning with relation to the question, which is, 1 think, which should interest the best men we have. Don’t overlook the fact that the projectors may be equipped with either of three kinds of light source, and that the size and shape of the auditorium are important factors in determining which you should ask for. Don’t just tell us you would ask for various things, but also tell us WHY you would want each one. Gray, Dobson, Bennewitz, Greene, and a lot more of the backsliders might reintroduce themselves with an answer to this one. No other question will be asked this week. place. However, that seems to be “out,” because it is the same with both projectors, and the out-of-focus effect is apparent only on certain kinds of scenes. I am wondering if it is not there all the time, only on some scenes the nature of the scene makes it more apparent. That, however, is “out” too, I think, because you would hardly fail to find that out for yourself. Help Wanted! Then, too, the image effect. I guess you’ve got me just plain stuck. I see no reason why any such effect should or could be attributted to the screen — or anything else, for that matter. If you have described the thing correctly it seems impossible. However, to settle the matter as far as concerns the screen, just swipe a few of friend wife’s bed sheets, if you have one (a wife, I mean), pin them together, and when you have a production which shows the effect badly, hang them over the screen surface after a. show some night, project the reel showing the effect worst, and check up results. If any of you can offer helpful suggestion to brother Early, write him direct, but, if you will, advise me as to what your idea of the thing is. A Simple Question For a Change fWROM a city in the Blue Grass State “4 comes this: “Where is the trouble? My picture is out of focus at the sides but focused perfectly in the center or vice versa. Both projectors are the same. Condenser not out of line, but think am using wrong combination. Distance condenser to aperture is 12 inches. Center of carbon crater to face of collector lens is 3)4 inches. Present combination 6.5 and 2.5 piano convex. No. 1 Cinephor projector lens. Its free aperture is 1)4 inches. Projection distance 82 feet, with a 16-fot picture.” The truble is not in lens system. You have given me all necessary information with which to check that up, except the one thing upon which it is based, and that is the diameter of^the carbon crater; also you have not said what kind of light source you have, though from what you have said, it is safe to assume it to be an ordinary arc. Film Doesn’t Lie Flat Either your aperture plate tracks are worn, together, probably, with the tension shoes, or for some other reason the film does not lie flat over the aperture. I guess it is safe to say the fault lies in worn tracks and shoes, because from what you say I assume the effect is not intermittent, as it probably would be if the fault were in the film itself, but is the same all the time. Examine the tracks carefully. Remove the plates and lay a perfectly straight edge on them. If worn, then install new plates, and (if also worn, as they surely would be) tension shoes. Also send in six dollars for a new Bluebook of Projection, brother, and study it. Now don’t some of you wise guys giggle and scoff at the question this good brother asks. It was not so long ago when YOU did not know this simple thing yourself; also there’s a LOT of other things YOU probably don’t know right now, but YOU lack the courage to ask, or the energy to study, therefore don’t get gay. No Instructions For Vitaphone I HAVE been asked by several projectionist correspondents why I do not publish a description of and operating instructions for the Vitaphone. The fact that another publication dealing with motion picture projection did so very fully has been cited by some of the said correspondents. I have not done so merely because neither a description or instructions for its handling would have any practical value. Mr. Watkins, Chief Engineer in charge of Vitaphone matters, himself advised me against it. In effect, he told me that such publication would be worse than useless because (Continued on next page)