Concepts - ETAP Lighting

www.etaplighting.com
light source
luminous
efficiency
luminous intensity
illuminance
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BASIC TERMS OF PHOTOMETRICS
LIGHT SOURCE
ETAP is always looking for efficient, economical and compact light sources. That is why we mainly use
fluorescent lamps and LEDs.
Fluorescent lamps are energy-efficient and have good colour rendering properties. They are widely
available and moderately priced.
An LED (light emitting diode) is a highly compact point light source, which radiates light in a single
hemisphere.
LUMINOUS FLUX F (lumen - lm)
Luminous flux is the energy of light emitted by a light source or luminaire per unit time.
Thermal management within the luminaire is a major consideration in our luminaire design, because it
influences the luminous flux.
EFFICIENCY (%) AND SPECIFIC LUMINOUS FLUX (lm/W)
Efficiency is the ratio of the luminous flux emitted by a luminaire to the lamp luminous flux.
The higher the luminaire efficiency at a given shielding, the lower the energy consumption.
Light output is currently not yet easy to publish for quite a few luminaires – especially LED luminaires.
Often the specific luminous flux is published in lm/W, which is not the luminous flux of the LED light
source itself, but of the full luminaire: how much light (lm) that luminaire radiates for the total power
used (W).
LUMINOUS INTENSITY L (candela - cd)
Luminous intensity is the luminous flux emitted in a given direction, per solid angle unit.
The luminous intensity therefore describes how the emitted light is distributed through the room.
For luminaires, luminous intensity is represented in the form of a polar diagram.
ILLUMINANCE E (lux- lx)
Illuminance is the luminous flux incident on a surface, per unit area. It is a measure for the amount of
light, but tells us little about the quality of the lighting.

luminance
shielding reflectors
shielding lenses
LUMINANCE L (cd/m²)
Luminance is a measure for the clarity of the source in a specific direction and is closely related to the
subjective brightness perception.
Control of the luminances of luminaires is essential for comfortable lighting.
Standard EN12464-1 imposes restrictions on average luminances, but ETAP also invariably pays attention
to limiting peak luminances.
SHIELDING
REFLECTORS
ETAP reflectors ensure that, for certain viewing directions, no direct light from the lamp can fall
into the eyes. This is referred to as physical shielding. However, it is equally important that no
mirror images of the lamp are visible in the reflector. This is known as optical shielding.
In ETAP products, the optical shielding is at least equal to the physical shielding. For reflector
shielding, the following terms are used:
• cut-off angle g
• shielding angle (complement of g)
LENSES
Optical shielding can also be achieved with lenses. A sophisticated lens definition ensures that
bright luminance of the light source cannot be seen in normal direction of view, thus satisfying
the requirements for luminance perception and UGR.
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ETAP
GENERAL

LED+LENS TM
MICROLUM®
ISOLUM®
EQUILUM®
MesoOptics TM
SOFTLIGHT
HaloOptics®
OPTICS
LENSES
LED+LENS TM
LED+LENS TM is a combination of efficient high-power LEDs and sophisticated lenses, used to
optimise light distribution.
LED+LENS TM provides high specific luminous flux and high visual comfort.
REFLECTORS
HRSilver TM - ALUMINIUM
ETAP uses HRSilver TM aluminium for the large majority of its reflectors.
This aluminium has an extremely high reflection factor (98%). As a result, HRSilver TM reflector
luminaires have a considerably higher efficiency, allowing you to save more energy.
SYMMETRICAL LOW LUMINANCE (SLL) BAFFLES
Parabolically shaped with a flat top cover. They provide good luminance control longitudinally
and transversely.
MICROLUM® BAFFLES
Parabolically shaped, with stepped top cover employing the Fresnel technique.
MICROLUM® baffles have low average luminances in all directions and significantly reduce peak
luminances.
ISOLUM® BAFFLES
Parabolically shaped, with continuously formed top cover. They result in low average luminances
in all directions and eliminate peak luminances.
EQUILUM® BAFFLES
Parabolically shaped on top and bottom sides. They prevent peak luminances and ensure perfectly
uniform shielding in all directions.
DIFFUSERS
MesoOptics TM
MesoOptics diffusers contain a precise microstructure that distributes the light in a controlled
fashion. The efficiency is about 30 % higher than that of luminaires using conventional diffuser
techniques. The result is rigidly and evenly illuminated optics without lamp silhouette and without
any disturbing luminances or colour interference.
SOFTLIGHT
Softlight luminaires clearly show where the light comes from. They use the entire surface of the
luminaire to evenly spread the light. They increase the brightness impression of the entire room.
HaloOptics®
HaloOptics® is a diffuser with a high transmission factor. Conventional diffusers create their
diffusing effect by including impurities in the material, whereby much of the light is lost.
HaloOptics® uses transparent inclusions, so that less light is lost and luminaire efficiency
remains higher.
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LIGHTING