The latest-arriving type of light
sources, the LED, is set to play
a major role in lighting in both
technical and civil contexts.

LED technology is by now
clearly carving out its role also
in cinema and television
lighting..

The LED abbreviation stands for
"Light Emitting Diode". Light is
given off during “conduction”
when a Positive-Negative (P-N)
junction is polarised and
converts the movement of
electrons from the Negative
pole towards the Positive one,
releasing photons (light).

As the conduction threshold is
low and as light emission is
proportional to the conduction
current, LEDs can be adjusted
with continuity - and with a
response time in the order of
nanoseconds. In products for
civil use, emission takes place
in the band of the visible light
spectrum.

The LED should not be confused
with the Photodiode. Unlike the
former, the latter is a P-N
junction DIODE built in such as
way that it increases the
inverse dissipation current,
switching an electric current
according to intensity changes
in the light striking it.

By now the small LED DIODE
performs the active signalling of
electric current or the activities
of whole circuits on electronic
panels, it lights up vehicle
position and brake lights, it will
soon replace all vehicle lights,
filling all dashboard functions.
It is the base of all known lit
displays, it supports (with a
suitable circuit) the electronic
flash units of digital and
traditional cameras, it will
definitively replace the back
lighting of LCD screens, and it
will ensure a cool and intense
light for all medical and
surgical use.

The simplest LEDs have a
arsenide or gallium phosphide
P-N junction. When crossed by
current, they give out a red and
green light respectively.

Depending on the materials on
the LED chip, you can produce
light in a variety of colors.

As mentioned, the commonest
LEDs produce colours that are
visibly strong and full. Some of
them give out Ultra Violet (UV)
and Infra Red (IR) wavelengths
for scientific use.

The LEDs instead that are higherpowered and that have more
complex structures produce
wavelengths that are very close
to that part of the CIE Colour
Space which identifies the region
of the colour temperatures, or
BLACK BODY LINE (BBL). The
light of these LEDs gives the
impression of white. There
however remain many
distinctions among the products
selected during construction
before one can define them as
LEDs calibrated for cinema and
TV photografic use.

The colour group zones of the
various LEDs are called Bins,
and are very wide horizontal
neighborhoods on the BBL line
and with tendency towards
green at the top and magenta
towards the bottom. Two
preferential spaces can be
distinguished: one for the warm
colour temperatures from
2,950°K to 3,500°K, the other
from 5,350°K to 8,000°K.

In both cases the LUMILEDS
produces 16 Bins overall, in
which high-power calibrated
LEDs may be chosen. It is worth
noting that the LEDs do not
emit in the ultraviolet range,
thus assuring greater safety
during use.

The careful mix of high power
LEDs from Bin of different
zones means the IANIRO
products achieve characteristics
of homogeneous chromatic
emission for use in recording
images, and are especially
suited for the various tones of
human complexion.

This special feature alone has
required long and careful study,
and for the first time has made
it possible to not filter the LEDs
upstream, thus reducing their
brightness.

The CRI (Colour Rendering
Index) objectively measures the
ability of a light source to
reproduce colours of its
subject. It ranges from 0 to 100.

For the LUMILED LUXEON LEDs
used by IANIRO the CRI is 70,
with the final assembly
reaching over 90 as a value
necessary for filming.

During the working life of LEDs
the response of colour and light
emission is the highest overall,
giving total safety during
filming sessions.

The LED units give off no heat,
thus allowing for a more
relaxed atmosphere for the
filming operations and for those
being filmed under the beam.
The IANIRO LED lights ensure
highly efficient heat dispersion
efficiency, according to
LUMILEDS technical standards,
thereby matching efficient
operation with operational
safety.

The low voltage also allows for
lower power to be taken from
the sources powering the
cameras, without reducing their
autonomy.

The possibility of reducing
power allows for the lighting
equipment to be dimmed
without compromising on colour
rendering response in all
shooting situations.

The use of high-power LEDs in
addition to secondary optics
and light beam collimators
allow for the light apparatus to
reach a high and efficient
overall emission that is
otherwise impossible with
conventional tungsten-quartz
bulbs.

The modular structure of the
IANIRO LED lighting units allows
for both in-line and cluster
assemblies to allow for heavy,
high-power light sets.
Complete and easy filtering
increases the flexibility of use
in all mixing situations between
different light sources.

IANIRO R&D is fully committed to expand the range of its LED lights : replacing the tungstenquartz bulbs by LEDs into the Film and Television lighting fixtures is a concrete engagement in the field of the energy saving.

Delivering lights more flexible,
chromatically precise, long lasting and bright it's a must and soon after the release of the location lighting systems IANIRO will develop key and soft studio lights for the video industry.