Motion Picture Herald (Jan-Mar 1956)

ftu4itmutn ^eatina Wide-Screen's Effect on Seating Plans FOR A MAXIMUM of realism, a motion picture should be presented to the spectator with the same conditions of viewing angle and perspective as those un der which the camera “saw” the scene. Obviously, these conditions can be met exactly for only a few seats in a commercial theatre auditorium. By going to the large picture, however, we have actually come much closer, potentially , to those ideal conditions for much of the seating area. With a 20-foot picture, the viewing angle varied from 54 degrees at the front seats, to around 10 degrees at the rear. With the new wide-angle camera lenses, seats which will give the best viewing angles are toward the front of the auditorium. By using a 30-foot picture, the viewing angle at the rear seats is increased to 18 degrees. For a 40-foot picture this extreme viewing angle is increased to 26 degrees. Thus the larger picture helps to give spectators in the middle and rear sections of the auditorium better resolution and greater perspective. {See comparative angles in accompanying drawing.) IVith technique which keeps magnification within its proper limits, forward rows need not be sacrificed — and to lose them would be adverse to the very objectives of the bigger, more voluminous picture. To enlarge the picture, then to move the audi ence proportionately back from it, would be to leave conditions pretty much as they were with the “postage stamp” screen. For the performance to dominate the field of vision and to give a high sense of “presence,” the audience must be as close to the screen as practical requirements permit. Screen Image Quality Three principal factors of screen image quality are : 1. Grain of the film. The grain, after having undergone chemical treatment, cannot be broken down into smaller values of picture information. The finer the grain and the better the chemical process, the more detailed the information that can be crammed into each tiny part of the film photograph. 2. Amount of magnification given the picture on the film. This means the amount of enlargement between aperture and screen. 3. Viewing distances — that is, the area in the auditorium from where the picture on the screen has the best resolution. This is an area in which the spectator should be able to see the smallest details in their true color and he should not be conscious of any space or bleeding of color between. Under traditional practice, good or acceptable resolution has been obtainable at a distance from the screen between two and five times the picture width. This means that for a 20-foot picture, the closest seats compatible with good resolution were 40 feet from the screen. If this same picture w'ere magnified to a width of 50 feet, the closest acceptable seats would be 100 feet from the screen. A 30-foot picture represents quite an increase in picture area over the traditional size, but {see accompanying drawing) it would not accomplish the total change required to liberate the picture from the confining and invasive architecture of a proscenium arch. To give the new picture freedom and scope, to provide a screen upon which the new type of productions may be shown to best advantage, it would be necessary either to widen the proscenium, or to move the picture in front of it. Changes in structure are often impossible, or prohibitive in cost, therefore it typically is the easier solution to move the screen ahead of the proscenium wall. In this case, the picture width could be substantially increased, at least to 40 feet in most cases, which would be more in accord with the objectives of wide-screen technique. With a picture of such size or larger, viewing angles become widened sufficiently to affect the traditional seating plans materially, while screen image quality (resolution of the film photograph) becomes more critical as a factor of distance between the screen and forward rows. Sightlines With Wide-Screen With a picture spanning at least 75% of the width of the seating area, and placement of the screen for the wider picture somewhat lower than it was located above the platform under former practice, sightlines must be more precise than formerly with respect to viewing positions in various parts of the auditorium. In the case of existing theatres, in which it is seldom, if ever, practicable to change floor pitches, adjustment of sightlines to a picture width around twice that of the previous one calls for use of chairs in the upper available widths (21 to 23 inches) in a variable stagger plan, possibly with double arm blocks. In determining a proper distance of the first row from the screen, practical considerations suggest anticipation of continued improvement in picture resolution. This makes it practicable to place the first row a distance from the screen equal to approximately two-thirds of the picture width. I PROSCENIUM 32' I 60' A comparison of viewing angles for three screen sizes, one of traditional practice, two representing wide-screen technique, as discussed in accompanying text. 20 Motion Picture Herald, March 24, 1956