Theatre Design & Technology - May 1965 - 24

Manufacturers of control systems have eliminated
many of the sources of operator fatigue and unreliability. Additional work should be done, however, in the determination of materials, coatings,
and system parts least conducive to eyestrain,
the shape and dimension of controls, the layout
of most frequently used controls for minimum
reach, and the di fferentiati on of control s wh ich are
otherwise alikein appearance. Serial information,
such as dimmer settings, has traditionally been
introduced into the machine using dials or calibrated sliders. The interest of the telephone
companies in push-button dialing may indicate
that a faster and more reliable model for data
insertion might be found in a typewriter keyboard
or desk calculator. A realistic appraisal needs to
be made of the time requ ired for an operator to
set a dimmer level accurately and also the time
required to set a large number of similar controls
without making mistakes. Experience with conventional ten-scene preset systems suggests that
there should be one person to adjust presets for
each fifty dimmers if cues are to be ready for
execution at the proper time and dimmer settings
reproduced accurately.

devices which will sense what is happening on
stage and which will determine the timing of
lighting changes which are cued to these happenings. As an example, control of the house lights,
opening of the curtain, and establishment of the
initial lighting distribution might be effected by
a properly programmed machine, leaving the
operator free to control non-predictable changes.
The machine might also be designed to perform
automatically certain sequences of operations
once the .initial move of the sequence has been
performed by the operator. For instance, after
the operator has blacked out a selection of instruments using a blackout switch, the machine
might set the controller to zero and turn itself
back on, thereby preparing for the succeeding
fade-in. There may be other commonly performed
sequences which the machine could be made to
handle without help from the operator.
Productions which are moved from one theatre to
another present a problem of control system and
cue sheet compatibility not encountered when a
production plays in only one theatre. Professional productions in general carry their own lighting
systems with them, thereby eliminating the problem of translating cue sheets from one control
system to another. Many advantages could accrue
to touring productions if theatres were equipped
with systems which made possible transposition
of cue sheets wi thout exten s ive Iighting rehearsals. One approach is the standardization of controls, dimmer response time, dimmer curve, systems of notation, etc. A second approach wh ich
permits system development through installation
and use of widely differing systems is suggested
by computer programmers who have devised
mean s by wh ich one computer can s imu late the
operation of another having different characteristics. Similar facility in lighting control systems should make possible the rapid translation
of cue sheets without stifling standardization.

Modern control systems are almost without exception intensity controls. When it is desired to
change the distribution of any of the other properties of light in the stage space, it is necessary
to do so using the intensity controls to substitute
a selection of instruments ha'ving one distribution for a second set having another distribution.
The result is wasteful in number of instruments,
dimmers and controllers since at any moment
many dimmers are inactive. It would be desirable
to be able with equal facility to control the other
properties of light from the system. Clearly the
first problem is not one of control system design,
but of the development of instruments which make
possible the changing of the properties of light
they produce. 6 If every instrument is to be subject not only to intensity control but to control
of the other properties of light, the system will
be extremely complex and without doubt additional operators will be necessary.

If the operator is to be sub jected to more and
more complex operations at the console, it will
be necessary to shift some of his duties to the
machine. At the present time, the human operator
determines the time at wh ich each Iighting change
will occur and the period of its duration. No one
familiar with dramatic performance and dedicated
to the proposition that a theatrical performance
must be free to vary, will tolerate a machine
which determines when and for how long a particular lighting effect will occur. Some thought
should be given, however, to the inclusion of

6. Instruments providing limited control of direction, color
and beam spread have been marketed, but have so for
been found impractical under theatrical production
conditions.

Probably the most time consuming and exasperating activity connected with the lighting of a
show is the recording of dimmer settings, switching and timing for each cue. During each performance, the operator is responsible for the reproduction of these same dimmer settings and
switching. The control information must, therefore, be organized into cue sheets which present
all information essential for operation of the
control system. It is usual for cue sheets to
record changes to be made rather than static
distributions to be maintained, thus eliminating
the repetition of control settings which do not
change. As a result, it is often impossible to
f"eproduce the ~ighting from a particular moment
of a production without running all cues from the
beginning of the act. The more closely the
recording process corresponds to the control sysotero, the less time must be spent in recording
and reproducing control settings. Certain of the
infinite preset boards have made the recording

IOSITT

THEAlRE DESIGN AND lEalNOlOOY

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