Theatre Design & Technology - Fall 2012 - 22

The vari*Lite vLX Wash
luminaire and its Luminous
Devices LED array.

LED sources which makes them easy to build into ribbons or
flat panels for decorative uses.
And yes, there is increasing use of LED sources in
theatrical production.
Current uses in theatrical production include Broadway,
where yards of LED lighting ribbons festoon and highlight scenery. Cyclorama lighting fixtures and large-scale LED screens
are also in use, along with a limited number of automated LED
spotlights. Similar uses show up in spectaculars and concert
production. But in all of these production types, the numbers of
LED-powered units is currently very small when compared with
the use of tungsten-halogen or arc light sources.
However, there is little reason to question the end of the
trajectory. LEDs are extremely energy efficient when compared to existing sources, and they last extremely long times.
Usable life ratings are projected to be between 25,000 and
50,000 hours.

20

theatre design

& technology

f

a

l

l

2012

The implementation of solid-state lighting will not be,
however, like some other massive shifts in our industry, which
took place almost instantaneously. Examples include the shift
from thyratron tube dimmers to SCR dimmers, and, within SCR
dimmers themselves, the shift to high-density dimmer racks.
This latter shift was accompanied by the almost instant abolishment of the patch panel. Another example is the introduction of
tungsten-halogen lamps, which replaced traditional incandescent filament lamps. With the introduction of LED fixtures, and
the possible concomitant changes in infrastructure, I suggest
that an equivalent adoption trajectory is the transition from gas
to electric lighting, which took nearly a decade.
The technology of LEDs dates back to the early 1960s, so
it is already half-a-century old. Only in recent years, however,
as efficiencies improved, have theatrical applications become
feasible. Since LED light engines have substantial advantages
over tungsten-halogen sources in efficiency and long life, what
is holding back their adoption into theatrical practice?
Several things: first, there is a limitation in the overall
amount of light that can be generated within a single package.
LEDs are very heat-sensitive, and operating at higher temperatures reduces their useful life. In order to keep the tiny LED
package cool, heat sinks, cooling fans, or both, are required.
You can see how massive some of these heat sinks are in the
photographs.
Second, the overall cost of an LED unit as compared to
a tungsten-halogen -source units multiplies the initial cost of
the unit by a factor of four to eight times or more. A lighting
budget based upon purchase of 100 conventional fixtures may
purchase only ten to fifteen LED fixtures.
Third, look at the photographs accompanying this article
and note that the LED configuration is different in each fixture
type. Now multiply this by the different designs of scores of
manufacturers, only some of them well-known and established.
Unlike the ubiquitous HPL lamp type used in tungsten-halogen
fixtures, there is no standardization of LED configurations in
our industry. Will the LED fixture you purchase today have a
compatible replacement LED module available should you
need it? Adding to the complexity of the overall fixture are the
electronic components, including the power supply, the driver
and other electronics, all customized for that fixture. Scores of
new LED fixtures are being introduced every year, but buyer
beware! Standards for testing light output and color quality, as
well as assessments of the useable life of an LED unit, are currently only the subject of numerous meetings among the several
participating standards organizations.
Finally, there are the questions of light quality, color mixing, and dimming, all of which are different from our current
sources. Unlike tungsten-halogen lamps, which produce a continuous spectrum of light throughout the visible range, LEDs
produce relatively narrow spectrums of light depending upon
color. Additionally, the color produced by an LED, and the Kelvin temperature of so-called white LEDs, varies as a result of
the manufacturing process. Thus, LEDs have to be (more or



Table of Contents for the Digital Edition of Theatre Design & Technology - Fall 2012

Contents
Theatre Design & Technology - Fall 2012 - 1
Theatre Design & Technology - Fall 2012 - 2
Theatre Design & Technology - Fall 2012 - 3
Theatre Design & Technology - Fall 2012 - Contents
Theatre Design & Technology - Fall 2012 - 5
Theatre Design & Technology - Fall 2012 - 6
Theatre Design & Technology - Fall 2012 - 7
Theatre Design & Technology - Fall 2012 - 8
Theatre Design & Technology - Fall 2012 - 9
Theatre Design & Technology - Fall 2012 - 10
Theatre Design & Technology - Fall 2012 - 11
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Theatre Design & Technology - Fall 2012 - 18
Theatre Design & Technology - Fall 2012 - 19
Theatre Design & Technology - Fall 2012 - 20
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Theatre Design & Technology - Fall 2012 - 24
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Theatre Design & Technology - Fall 2012 - 27
Theatre Design & Technology - Fall 2012 - 28
Theatre Design & Technology - Fall 2012 - 29
Theatre Design & Technology - Fall 2012 - 30
Theatre Design & Technology - Fall 2012 - 31
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Theatre Design & Technology - Fall 2012 - 37
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