Movies for TV - Early Television Foundation

80 FUNDAMENTALS
All the necessary amplifying equipment and equalizing circuits
for correcting the frequency response of the signal are contained
in the racks on each side. The large meter on the upper left-hand
side is a frequency meter for checking low frequencies when adjust-
ing the equipment. It will be seen that most of the film recording
units bear a strong resemblance to each other, or to camera design,
which is not surprising since they are all designed for a similar purpose.
The recorder is proper mounted in the center with the two
film magazines on the upper surface.
Mobile 16 mm RCA Recording Equipment
In Figure 3-17 is
shown the latest RCA 16 mm equipment for mobile use. It was
built into a truck and forms part of the studio on wheels which is
used by Coronet Instructional Film Company of Glenview, Illinois,
for the production of instructional films. The recorder is a standard
RCA PR- 2 3 film recorder modified to permit the recording of
direct-positive sound tracks. This may not seem much of a problem,
or very necessary, especially since direct-reversal film can be used.
But, since the use of direct-reversal film sometimes introduces other
difficulties, its use is not always desirable. It is not a simple matter
to design a light valve which will produce a positive picture, for
the valve operates by allowing more or less light to fall on the film.
The stronger the signal, the stronger the light, (the positive film is
like that but the corresponding part of the negative has a large, dark
area in the identical spot where the positive is clear). Therefore,
the problem is to get the same dimensioned areas, but with the
colors reversed, as in the positive and negative films in Figures
3-13A and B. Variable-area RCA recording is, of course, used.
As far as the costs of double system versus single system are
concerned, the extra film for a double system recording costs about
$15 to $16 per 1000 feet, which is the cost of positive film. In the
case of single system, the only cost is for picture film. It is possible
that use of the double method might require the services of extra
technicians to operate the sound recorder since it is separate from
the camera proper. The advantages of single and double systems
are discussed later.