Quality of light and the - Philips Lighting

iNtERViEW
4 | Lightspec | issuE6/NoVEMBER2012
Quality of
taking the
measure of
LED light
quality.
the consumer buying light for the home expects
all of the above, but also a light source which
works well and gives a pleasant light when used
with transformers and dimmer switches.
For the office user quality of light might be
characterized by the uniformity of light coming
from the luminaire, illuminating the work space
with a homogenous light
pattern. Everyone has their
own expectations and ideas
concerning quality of light.
Quality of light has played an
important role throughout
the ages of conventional
light sources and luminaires
and has generally improved over time. Most
lighting professionals will recognize the difference
in quality between the halophosphate and
triphosphor fluorescent tubes, or the difference
between the flickering of electromagnetically
driven fluorescent luminaires versus the smooth
high frequency electronic fluorescent luminaires.
Consumers have always been able to recognize
the difference in quality of light between
compact fluorescent lamps and incandescent
light bulbs in the home, even if they could not
voice the technical parameters why. a colour
rendition of CRi 80 is not the same as CRi 100.
Nor is a lamp lumen run up time of 5 minutes
the same as instant maximum light output. they
experience it, feel it and know it is different.
the main example of improvement in quality
of light that many lighting professionals will
“Consumers have
always been
able to recognise
quality of light.”
annetta Kelso,
senior Marketing Manager LED systems,
Philips Lighting
www.philips.com/lightspec
Quality of light encompasses many things and these can be very different
depending on the application or the person you ask. For the clothes retailer quality
of light might mean colour rendition and the depth of saturation of colours in
material, whereas the food retailer might see quality of light as the consistency of
the colour temperature of white lamps in the ceiling, or the psychology behind the
choice of a particular colour temperature.
remember is the switchover from quartz metal
halide lamps to ceramic metal halide lamps in
1994. it was a great relief for retailers to be able
to get rid of the dreadful pink, green, blueish
white colour shift visible from lamps right next to
each other. sales of lamps with ceramic discharge
technology, such as the Philips MastERColour,
rose dramatically year
upon year and became
firmly established in lighting
specifications. Ceramic
discharge lamps are
now one of the ultimate
examples of high quality of
light, having made continuous
leaps forward in spectral
composition and control of the light.
Quality of light in general has always been
an issue that has surfaced, been solved and
resurfaced again.
// Colour consistency
When a new technology comes in to an existing
market there is usually a period in which
the new technology does not yet outperform
the incumbent technology, but offers additional
features that are so attractive that people start
overlooking the (temporary) lower performance.
think of flat screen televisions, or laptops over
desk top computers. With the advent of LEDs
as a credible light source for general lighting, the
same pattern could be seen. Lumen packages
and efficiency were not better than certain
conventional light sources, but general expectation
was that this was just a matter of time.
issuE6/NoVEMBER2012 | Lightspec | 5