Theatre Design & Technology - Oct 1966 - 49

of the house; and one in the light control booth. In our
choice of these we felt that the stage manager certainly
should be in total control of the entire system at all
times. During production or during set up, certainly the
lighting designer or the technician, who is sitting out in
the middle of the house, should be able to talk to these
people without having to run back and forth from the
stage. We also felt that if the person operating the
light console wanted to talk to someone in the beams and
this man was away from the squawk box adjusting an
instrument, or had his headset off, he should be able
to get into this particular area without haVing to walk
out into the balcony and scream at the top of his voice.

So we added these command stations, and on each there
are - certainly in selected areas such as the grid, the
beams and possibly the trap room - remote relays, so
one can receive and transit from these remote locations.
This new combination system has been specified for several future installations, and we hope that we have solved
most of the inter-communication problems associated with
theatre operation with this new system.
We are certain that as these new devices are put on the
market, we will be 10 a much better position to incorporate them as newer and better means of communication
in the theatre.

20000 - WATT IODIDE QUARTZ LAMPS
Thomas M. Lemons

I.R. CODE: equipment - lighting - lamps

The Sylvania 2000 Watt Iodide Quartz lamp has made a
major contribution to the Theatre lighting field. It is the
highest wattage, 120 volt I. Q. lamp to be marketed to
date. The length-to-diameter ratio of its coil makes it
ideal for the development of associated optical systems.
As with all compact filament I. Q. lamps, its ability to
operate in any position and its uniform light output and
color temperature throughout its Iife makes it an ideal
source.
Figure 1 shows this lamp in comparison to the conventional 2000 watt incandescent theatrical lamp.
The2000 watt I. Q. lamp was first announced in New York
City at the IES Theatre and TV symposium in June of
1965. The first installation of it was made in August
1965. Since then the lamp has been applied in fresnels,
ellipsoidals, scoops, beam projectors and spotlights. In
each case the performance of the fixtures have been
increased in either light output or lamp life.

In the case of the fresnel, about a twenty-five percent
increase has been obtained in the beam performance.
With the ellipsoidal the beam increase has been greater
than fifty percent. This lamp in an eighteen inch scoop
has provided sixty percent beam efficiency and over seventy percent field efficiency. Again, a beam performance
increase is obtained in the beam projector. In the case
of follow spotlights or special effects projector spotlights
this lamp with a 150 hour life has equaled the light output performance of present incandescent twenty-five hour
lamps.

2000·wall Iodide Quartz Lamp compared wtlil a standard G·tYpe incandescent theatflcal lamp.

Double·ended High Watlage Series
Iodide Quartz Lamps. 110 wall 30·
150·500-2000 110urs;
2000-wall
150 hours. Photo Paulus Leeser!

The 2000 watt lamp's characteristics are: 120 volts,
45,000 lumens, 3100 0 K color temperature, 150 hours
life, and it will operate in any position. Its coil is approximately 5 8 inches long and 3/8 inches in diameter.
Its contact spacing is 5.625 inches which makes it interchangeable with the family of four 1000 watt lamps
who range from 3000 0 K to 3400 o K. Figure 2 shows this
family of 1000 and 2000 watt lamps. Other 2000 watt
lamps will soon be developed to further expand this
family of lamps.
The use of I. Q. lamps in theatre lighting equipment is
not without problems. Because of the small size of such
lamps as the 2 000 watt I. Q. lamp, there is a t~ndency
to develop or adapt small fixtures around them. This
can be done with extreme care, but all too often problems result. The size and wattage of long-established
fixtures were often a result of housing and component
temperature limitations. Unless methods which will avoid
these limitations are incorporated into the design, the
size of the fixture should not be changed.

I. Q. lamps are revolutionizing theatre lighting equipment. Sylvania's leadership in
the development of compact filament I. Q. lamps has now been furthered by the
2000 watt lamps. Its universal use in theatre equipment and the resultant increases
in performance verifies the importance of this development.

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