Page 86 - Between light and shade

between light and shade, TRANSPARENCy and reflection

the USSR a short time ago, are frequent users of
luxurious halogen bulbs and their flattering light
for homes, as well as for buildings dedicated to
shopping, culture or leisure pursuits. This will
not last for much longer.

Fluorescent tubes are commonly used for
workplaces. What a contrast with geographic
areas that have been left behind, such as Africa,
South America and large parts of Asia! Here,
energy insecurity, for whatever reason, forces
people to almost exclusively use fluorescent
tubes, which are so much more efficient. This
nocturnal atmosphere, which we see as “primi-
tive”, actually represents a particularly ethical
use of available energy resources and technolo-
gies.

Light-emitting diode bulbs (LEDs) 100 slowly
appeared in the 1990s, becoming potentially the
most effective light source to date, with lumi-
nous efficacy of 80 to 150 Lm/W, a usable life that
currently exceeds 80,000 hours (approaching
100,000 hours) and a color rendering index (CRI)
that has already reached 95% for certain LEDs,
and is constantly improving. The new light
source, requiring a low voltage power supply (12
or 24 Volts) is one of the embodiments of the
third industrial revolution, which is vigorously
driven by the Internet. It is consistent with local

100 DEL (Diode Électroluminescente) in French.
86