Movies for TV - Early Television Foundation

168
FUNDAMENTALS
any, will have been reached. At that time, of course,
it will be
desirable for the person engaged in television or the associated
arts to learn all he can about the one chosen. For this reason,
therefore, only brief descriptions will be given.
CBS Color Television System The system with which the
author is most familiar is that developed by Dr. Peter Goldmark
of CBS. This has been demonstrated in many parts of the country
with highly satisfactory results. The colors are vivid and lifelike
and add tremendously to the value and appeal of the picture. The
to construct and would
apparatus is extremely simple and easy
not be beyond the scope of any person of average intelligence. In
describing the operation of the system,
it should be noted that the
resolution, i.e., the number of picture elements, or lines for ease of
discussion,
is much lower than that for black and white televi-
sion using the same transmission characteristics. However, the eye
accepts color much more readily than it does monochrome and,
hence, is more easily able to separate objects than it would with
black and white television and the same degree of definition. Color
fidelity is excellent and is actually better than color in motion
pictures because it can be controlled from second to second even
while on the air. The number of lines in the standard is system
525 while in CBS color it is 405. This is a difference of only 120
lines, but the apparent definition is quite as good as a black and
white picture, even though the actual definition is less. After all, it
is what the observer thinks he sees that counts most!
The mechanical system proposed by CBS uses a filter disc con-
sisting of segments of red, blue, and green filters revolving in front
of the camera tube at 1440 rpm. This results in the transmission
of three separate, incomplete images for each picture or frame
since the filters pass only one color at a time. At the receiving end,
the colors are re-inserted by the addition of a similar disc before
the tube. This disc has to be in phase synchronization with the
transmitter so that when the red filter is in front of the camera
tube a red filter is also in front of the receiving tube. With a field
repetition rate of 144, or 72 frames per second, 405 lines are trans-