Radio age research, manufacturing, communications, broadcasting, television (1941)

Color Book jor TV Scenery Designer By Albert W. Protzman, Technical Pruduction Director. Niitiomil Brotulcastitig Co. I MAGiNE a television stage scene as it would be viewed from the TV studio: The set designer has ex- ecuted the background in the soft tones of grayed gold; the star is wearing a gown of ultramarine blue; the leading man is clad in a suit of medium gray, and the dominating piece of stage property is a divan covered in a brocade of warm green. To the studio audience, the visual picture in color is a satisfying one, impressive and in the proper mood of the play. But strangely, the thousands who are watch- ing the same scene on their home TV receivers in monochrome are left cold, unresponsive, unimpressed. To them, the video screen picture — in sharp distinc- tion to the scene viewed by the studio audience — appears flat with an almost complete absence of tonal contr.ist between the costumes of the cast and the stage properties and scenery. In this imagined scene, some vital change has taken place between camera and re- ceiver screen to nullify the best work of designers, pro- ducers and cameramen. Unfonunate situations similar to this one have not been uncommon in television. The basic cause was the inability of the TV camera to convert the different colors of the scene into correspondingly contrasting shades of black and white. In the particular setting just described, the grayed gold, ultramarine blue, gray and green would have appeared on viewers' screens as a monotonously uniform tone of slate gray. But NBC has taken positive steps to see that such incongruities won't happen again on its network. After months of methodical labor, the author and Cliff Stiegel- bauer. NBC Supervisor of Design, have completed preparation of a reference book which removes all element of chance in selecting colors and color com- binations for the most effective black-and-white TV presentations. Preparation of a reference book of this kind would have been useles in the early days of television when the iconoscope was the standard camera tube, because the "ike" was not stable in its color response." Different tubes responded in different ways. But the RCA image orthicon — the present standardized camera tube — is being mass-produced with a dependable and specific spectral response. This response was used as the start- ing ptiint for the NBC color charts. T When the study of color versus bl.ick and white w.is begun, it was essential first to establish a workable range in the gray scale, that is, from light gray to near black. As a basic source of comparison it was decided to utilize the accurate and standard Munsell Gray Scale. The Munsell system grades tones from black to white and arbitrarily numbers them from 1 to 9.5, but be- cause the television system cannot successfully tolerate this wide contrast, it was necessary to confine the range between ii2 black to i±8.5 white. Munsell #2 black reflects only ?i^l of the light striking it while the #8.5 hue, called "television white," reflects 63.5% of incident light. By actual tests it was found that a video picture could be more accurately reproduced if tlic- reflectance of scener)', whether in color or in monochrome, were held within this restricted contrast range. Preparation of the NBC Color Book was a long, tedious job. There were 192 colors to test and each color was broken down into four tints and three shades. In its final form, the NBC book — which is not available for general distribution — consists of 14 pages, iCnntiniicJ on pai^c 32) The author (left) measures the temperoture of the studio illumination as ClifF Stiegelbouer holds a red-orange cord against a gray scale. The comparison shows that this particular hue will be reproduced on TV screens as Munsell =7 gray. RADIO AGE 25