American television directory (1946)

HOW LARGE A SCREEN? When is a small screen too small — a large screen too large? A frank discussion of factors that are certain to influence the public and shape teleset buying trends. By DR. ALLEN B. DuMONT President, Allen B. DuMont Laboratories, Inc. H ow large should a television screen be? The answer is: Large enough for comfortable enjoyment of television en¬ tertainment. One might as well ask: Which should I drive, a bus or a coupe? The answer depends, naturally, on how many persons I wish to accommodate and just how pleasant I wish to make their accommodations. It is entirely possible to install too large a screen for the size of a room. And this extreme is just as absurd and inadequate as inviting all one’s neigh¬ bors to crowd about a tiny screen to witness a much-heralded’ sports event. There are yardsticks, of course, for de¬ termining a satisfactory screen size. Suppose we discuss the several factors affecting this problem. Proper Viewing Distance First, there is the proper viewing dis¬ tance . . . best illustrated by a motion picture theatre. Seats from about the eighth row to the twentieth, right down the center, are apt to be taken first. Then the rear rows fill up. Late-comers re¬ luctantly accept the side seats. And the last to come must fill the rows down front. Here they are very much aware of many minute imperfections in the film. Yet further back in the house this same film seems perfection itself! Every person — according to his eye¬ sight — naturally selects a distance from the screen that is most satisfactory for him. Thus the proper viewing distance varies with each individual. The aver¬ age person selects a distance roughly 10 to 12 times the height of the picture. When a television receiver is installed in your living room you have a counter¬ part of the motion picture theatre. The size of the television screen automa¬ tically determines the proper viewing distance. Thus, an 8" x 10" image will be viewed most satisfactorily by the average eye at a distance of approxi¬ mately 8 feet. Sitting nearer only makes the viewer conscious of the scanning-line structure and correspond¬ ing texture of the image. Moving far¬ ther away improves the pictorial reso¬ lution until the image is on a par with theatre movies — but the picture may become too small for comfortable view¬ ing! Hence the importance of sitting within the proper viewing distance of 8 feet. The giant DuMont 20-inch tube tele¬ set, providing a \ZVi" x 18" image, calls for a proper viewing distance of from 12 to 15 feet. If the sitter moves nearer, he becomes aware of the scanning-line structure of the image. Beyond 15 feet, the sitter still enjoys a comfortable screen size with excellent pictorial defi¬ nition. Any screen size viewed at the proper viewing distance provides about the same pictorial detail, everything else being equal. The midget teleset with its 3 V2 " x 4 V2 " image, aimed at the very low price market, produces just as sharp an image as the projector-type teleset which projects a 3' x 4' image upon the wall of a large living room or class room. In fact, the midget screen image is apt to appear needle sharp, but only because its scanning-line struc¬ ture is spaced so closely together that it passes unnoticed when viewed from a couple of feet away. Size of Audience The second factor to consider is the size of the viewing audience. With the midget teleset, whose image is viewed at no greater distance than 2 feet, only one or two persons can comfortably follow the television entertainment. Even so, these lookers-in complain of the same cramped feeling that went with early radio sets when earphones virtually chained the listeners-in to a nearby chair. Then the loud-speaker came along to provide freedom of ac¬ tion. Except for individual use, or as a second or third teleset in a home already enjoying a large-screen tele¬ set in the living room or playroom, the midget teleset has very definite limitation. The larger the television picture, the greater the audience that can be com¬ fortably accommodated, and the greater the feeling of freedom. With an 8" x 10" image, you are no longer peeping at the show through a knothole, so to speak, but rather are enjoying a pretty good seat, provided the room is not crowded. From six to ten persons can be seated in two or three rows, and everyone of them will be able to enjoy the show. But let the home audience run up to a dozen or more and a larger screen is necessary. This is where the 20" tube becomes the logical choice, with its 131/2,'x18" screen. I predict that this size will be the most popular for home use since it can comfortably accommo¬ date up to twenty televiewers. If one has a huge living room or playroom for the television show, with audiences at times numbering two dozen persons or more, then the 3' x 4' image obtainable with the projectortype teleset comes into its own. How¬ ever, this set spells real luxury and commands a luxury price quite beyond the vast majority of future television set owners. Freedom of Action The size of the audience is not, of course, the sole factor influencing one’s choice in favor of larger screen sizes. I again bring up the matter of freedom of action. It is certainly comfortable in the extreme to have a 3' x 4' projected image upon the wall, which can be viewed from any chair in a huge room. Many persons, to whom cost is no handicap, will doubtless prefer a pro¬ jected image. It is consonant with gra¬ cious living, with expansive living rooms and playrooms. The DuMont organization has de¬ signed and put into production a choice of telesets ranging from the smaller screen sizes at popular prices to the largest direct-view telesets, and also is producing a 3' x 4' projector type for those seeking superlative performance even if it does cost as much as a good automobile. Because we are manufac¬ turing all sizes and types, I can im¬ partially point out the good points and disadvantages of each. It is my sincere belief that directviewing television offers the most for the money. The DuMont organization has pioneered the giant 14 and 20-inch cathode-ray tubes and was the first to offer large-screen telesets based on the use of such tubes (as early as 1939). We still favor the direct-viewing meth¬ od for which we make the necessary giant tubes. Direct-View Advantages The principal advantages of directviewing television are high light bril¬ liance, better contrast range, wide-angle viewing, lower accelerating voltage, longer life, better resolution, less align¬ ment difficulty, and simplicity of the 16