Color Television Film Recording from a Trinoscope

Videotape is most commonly transcribed to film by photographing a shadow-mask picture tube. Although this method is capable of reasonably good results, shortcomings of the picture tube limit further advancements. It is generally recognized that improvements are needed mainly in resolution and color saturation. To achieve improved quality, the authors designed and built an experimental trinoscope recorder employing three separate picture tubes, one for each primary color. The three separate images are optically combined, registered, and photographed as a single image. The trinoscope is superior to the shadow-mask tube in several ways. It can give higher resolution, the phosphors can be selected to match the sensitivities of the recording color film, and it can produce a much brighter display. Slow films in the ASA 10 range can easily be exposed. — High-quality solid-state electronics provide a very stable display with good registration and permit extensive signal processing. The display tubes have flat faceplates of 5-in (127-mm) diameter and the phosphors are P20 for green, P22B for blue, and P22R-sulfide for red. A paper on improved shadow-mask recording techniques has been published by the authors¹ and procedures for setting the trinoscope for correct color rendition are similar to those described in that paper.

Print ISSN

0361-4573

Published

1974-09

Content type

Original Research

DOI

10.5594/J06923