30 MAY/JUNE 2017 LEDsmagazine.com
conference report | SIL 2017
the use of white-light products that operate continuously and that also have violet
LEDs at work. So a space such as a sports
locker room can be continuously disinfected.
Costello said the potential is for 90% of bacteria in a room to be destroyed in one day.
One Vital Vio luminaire model also includes
a concept called Eco-mode that extinguishes
the white light when people are not present and cuts energy usage by only powering the violet LEDs. The company has developed LEDs specifically for the application. It
does sell some lighting products today, but
the business model is ultimately focused on
partnerships with lighting companies.
Of course, horticultural lighting technology
was presented at SIL, although we also have
a dedicated series of one-day events specifically focused on horticulture with the next
set for October 17 in Denver, CO (horticul
Vail, co-founder and COO of vertical-farm
specialist Local Roots, neatly described the
opportunity. He said food is a $6 trillion
industry — only considering sales to consumers and not production or distribution.
And there are myriad problems with the current food production industry. Vail said that
97% of the produce consumed in the US is
grown in California or Arizona and the average ship distance is 2000 miles. Moreover, he
said population growth would require 70%
more agricultural land by 2050 using traditional farming techniques.
Vail said vertical farms enable 300× more
production per square foot and use 100× less
water. And Local Roots is installing farms
in fully-computer-controlled, used ship-
ping containers that can be located in pop-
ulation centers including in downtown Los
Angeles for Local Roots (see a recent arti-
cle for more details: http://bit.ly/2f WkMA1).
Vail said horticulture represents a $10B per
year opportunity for LEDs.
Quality of light
Back to general lighting, SIL would never be
complete without some presentations on light
quality, color rendering, and usable metrics.
One issue that continues to confound is what
is white? That’s a question that
is often answered with a CCT
metric, but that truly depends
on spectral power distribution (SPD), and often on human
Xicato is one company that
has focused on excellent color
rendering in its LED light
engines since its inception.
But the company is also being
asked for SPDs tuned to spe-
cific applications. For exam-
ple, CEO Menko DeRoos said
through Xicato’s experience
in retail stores, it learned that
cosmetic counters need a light
that is “way off the black-body
locus [BBL].” He described the light as look-
ing pink when shined on a white wall. But
he said stores using that light for cosmet-
ics sales had reduced merchandise returns, a
notorious issue in cosmetics, to less than 1%
while also boosting sales.
And clearly we have yet to
hear the final chapter on color
metrics. The final SIL keynote
came from a Hollywood legend
named Jonathan Erland, who
founded The Pickfair Institute
focused on lighting for cine-
matography (Fig. 7). Erland
said 3200K tungsten lighting
remains the gold standard for
cinematography because of a
broad and smooth SPD. He said
the discontinuous SPDs of LED
and HID sources don’t work well
in the application, although we
have been guilty many times of
saying the latest LED lighting can serve in
place of any legacy source.
If you have a chance to see Erland present, take it! His insight extends into general lighting. He explained the differences
between a camera and a human observer
and how the right camera-optimized lighting makes for a good human-observed movie
experience. And he described shortcomings
in metrics such as TM-30 ( http://bit.ly/2p
pmJ Yx) and CQS (color quality scale).
The Hollywood-centric Academy of
Motion Picture Arts and Sciences has been
working on a color metric that it calls the
spectral similarity index (SSI). And there
is an accompanying software platform
called the Academy Color Predictor. Erland
believes the work will also prove invaluable
to lighting designers trying to discern how
humans will experience light in a space.
In closing, let’s return to the disruption-cen-
tric theme advanced by Strategies Unlimited’s
Smallwood. There are many great opportuni-
ties in SSL, but many are centered around the
Io T and new applications that would be ser-
viced by other industry or technology sectors
were it not for net worked lighting.
Smallwood characterized networked
lighting as a Trojan horse that rivals the PC,
the Internet, and handsets as a gateway to
the computing cloud. His point was that net-
worked lighting can be the backbone of Io T
applications in buildings. Lighting is ubiqui-
tous and always powered. Moreover, street-
light networks can be the backbone of smart
city applications. Hold on for a wild ride.
FIG. 7. Jonathan Erland comes from a cinematography
lighting background, and warned that all existing
color metrics have flaws.
FIG. 6. Vital Vio’s Christine Costello made a
compelling presentation about the potential to kill
90% of bacteria in one day using a combination of
white and violet LEDs.