PRIMEX – Lighting Lexicon for LED Technology and Lighting Design

LED Technology Explained Simply Modern LED systems are powerful, versatile, and energy-efficient. However, behind every professional lighting solution lie technical parameters and terms that are crucial for planning, design, and application. Our compact lighting lexicon provides the most important basics – practical, understandable, and professionally sound.
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PRIMEX – Lighting Lexicon for LED Technology and Lighting Design
LED Technology Explained Simply Modern LED systems are powerful, versatile, and energy-efficient. However, behind every professional lighting solution lie technical parameters and terms that are crucial for planning, design, and application. Our compact lighting lexicon provides the most important basics – practical, understandable, and professionally sound.

KELVIN (K) – Color Temperature

Color temperature determines whether light is perceived as warm white (cozy) or cool white (activating).

The lower the Kelvin value, the warmer the light:

  • 2700–3000 K: Warm white – e.g., hotel, lounge, living room
  • 3500–4000 K: Neutral white – e.g., office, retail, exhibitions
  • 5000–6500 K: Cool white / Daylight white – e.g., industry, medicine
  • Tunable White (2700–6500 K): Dynamically adjustable, e.g., for HCL applications

 

Luminous Flux

Luminous flux refers to the light output (radiation) of a light source in all directions. The emitted light output is measured in lumens (lm).

Luminance

Luminance describes the ratio of the size of the illuminated area to the luminous intensity. It is measured in candela per unit area (cd/m²).

Reflection

Reflection is when a light beam strikes a surface and is thrown back by it.

CRI – Color Rendering Index

CRI describes how naturally colors are rendered under a light source. Scale: 0 (poor) to 100 (daylight reference)

The lower the Kelvin value, the warmer the light:

  • CRI > 90: Very high color rendering – for showrooms, museums, retail with colored products
  • CRI 80–89: Standard quality – e.g., for offices, gastronomy
  • CRI < 80: For industrial or outdoor areas with lower requirements

 

LUX (lx) – Illuminance

LUX indicates how much light (lumens) falls on a specific area. 1 LUX = 1 lumen/m² Recommended illuminance levels by application: Office workstation: approx. 500 lx Sales areas: 300–750 lx Museums / Galleries: 200–300 lx (targeted) Entrance areas: 100–300 lx

Beam Angle

The angle at which light is emitted from the light source is called the beam angle. It is measured in degrees (°).

Glare

Glare impairs vision and is perceived as a disturbance. Glare is strenuous for the eyes and leads to fatigue and loss of concentration.

Light Colors

Light colors not only influence our visual perception but also our emotions and feelings. By consciously choosing colors, we can specifically design the atmosphere of a room and thus create the desired ambiance.

Light itself is energy in the form of electromagnetic radiation that propagates in waves. The light spectrum extends from long-wave infrared rays over the light visible to our eyes, to short-wave ultraviolet rays.

Depending on the wavelength, we perceive different colors: Red, Orange, Yellow, Green, Blue, Indigo, and Violet. The totality of all wavelengths results in white; black light represents the absence of reflected light.

The associations we have with certain colors are diverse. Yellow quickly evokes thoughts of sun, warmth, and joie de vivre, while blue awakens memories of the sea. Red makes us think of fire and passion. Bright, bluish tones create the impression of spaciousness, airiness, and coolness, while orange and red tones have a warm and stimulating effect.

The brightness or intensity of a color also plays a role. Dark colors make room contours visually disappear, causing the boundaries of a room to blur for the eye. In contrast, white gives rooms freshness, spaciousness, and clarity, conveying a feeling of openness and lightness.

With the help of color mixtures, different light accents can be set. In the field of lighting technology, there are two different methods to create new light colors:

  • additive color mixing (The primary colors red, green, blue are mixed; an equal ratio of the 3 colors produces white)
  • subtractive color mixing (The primary colors yellow, magenta, and cyan can absorb parts of the light spectrum)

 

Light Intensities
  • Luminous intensity is a physical quantity that indicates how much light a light source emits in a specific direction.
  • It is specified in the unit candela (cd) and depends on various factors, such as the power of the light source, the beam angle, and the efficiency of the light source.
  • Brightness depends on the luminous intensity of the light source as well as the distance to the light source and the reflective properties of the illuminated surface.
What is indirect lighting?

With indirect lighting, the light source itself is not directly visible. The light falls indirectly onto the illuminated surface through reflection or scattering. This leads to a diffuse and uniform illumination of the room.

The Advantages of Indirect Lighting

  • Indirect lighting has a glare-free and pleasant effect. It is particularly suitable for areas such as hotel rooms, hallways, halls, and restaurants.
  • Due to the diffuse illumination, no harsh shadows or sharp reflections are created, but soft and uniform light.
  • The room is perceived as optically larger.
  • Contrasts in the room are softened and an atmospheric ambiance is created.
  • Often, the light sources of indirect lighting can be dimmed to adjust the brightness and create an individual lighting mood.
  • By selecting the light color, an individual room design can be achieved.

What is meant by reflectance?

Reflectance indicates what percentage of the light hitting a surface is reflected (radiated back). Reflectance depends on the nature and color of the surface. Light surfaces generally have a higher reflectance than dark surfaces.

  • A reflectance of 1 means that the surface reflects all incident light.
  • A reflectance of 0 means that the surface reflects no light and completely absorbs or transmits it.

Here are some examples of the reflectance of different surfaces:

  • A white ceiling or wall reflects up to 85% of the light.
  • A reflectance of 0 means that the surface reflects no light and completely absorbs or transmits it.
  • Red bricks reflect up to 25%.
  • A black floor reflects no light (0%).
What does dimmable mean?

A dimmable light source allows the intensity of the light to be regulated. This is usually done by using a dimmer that controls the current flow to the lighting. By dimming the lighting, the atmosphere of a room can be significantly influenced. Depending on mood, activity, or personal preferences, the brightness of the light can be adjusted.

What are the advantages of dimmable LEDs?

  • Flexibility of brightness control. It offers in restaurants and hotels the adaptation to different times of day and moods. In offices, the brightness can be individually adjusted to the needs of the employees, which can positively impact productivity and well-being.
  • For offices or reception areas, dimming allows the setting of optimal lighting for workstations according to the workplace regulation DIN EN 12665.
  • Dimmable LEDs contribute to extending the lifespan of the light sources. By reducing brightness, heat generation is decreased, which in turn reduces the stress on the LEDs and extends their lifespan. This leads to a longer service life of the light sources and lower maintenance costs.
  • The lighting of a room can be adjusted according to needs and occasions. For a cozy evening at home, you can dim the light to create a warm and relaxing atmosphere, while brighter lighting may be required for reading or working.
"Flicker Effect" in Film Recordings of Light Frames

Primex uses "low-flicker" LEDs in its light frames. For a significant surcharge and with significantly extended delivery times, special "flicker-free" LEDs can be procured and installed. These are normally used in practice only for light sources that are used for illuminating photo motifs or film recordings.

The camera's aperture and exposure parameters have a significant influence on the "flicker" result in film recordings. With optimized settings, "flickering" can be minimized or, ideally, even completely prevented.

However, this requires specific expertise, as ambient lighting and other factors also have an influence.

For film recordings of light frames, it is recommended not to use dimming, as dimming is known to increase flickering.

Light at the Workplace

The Effect of Light at the Workplace

Concentration-Promoting Work Atmosphere and Increased Well-being

Well-designed workplace lighting has a positive impact on employee health and work performance. This is because light has a direct influence on our mood, concentration, and productivity.

Therefore, when designing workstations, you should consider some essential factors: Brightness and Color Temperature: A bright and neutral white (3,300 – 5,300 K) to cool white (> 5,300 K) light color is particularly recommended. Bright light has a stimulating effect and prevents the production of the sleep hormone melatonin. Instead, bright light promotes alertness and concentration. It is advisable to also include daylight in the lighting, as it acts as a natural energy source and positively influences mood.

Mix of Direct and Indirect Lighting: Indirect lighting creates uniform illumination of the room and reduces shadow formation, while direct lighting of the work surface provides targeted light for specific tasks.

Avoidance of Reflections and Glare: Avoid reflections on screens and other reflective surfaces, as they impair visibility and disrupt concentration. By using glare-free luminaires and careful positioning of the lighting, this problem can be effectively minimized.

Consideration of Age and Vision: The age of employees should be considered when designing workplace lighting. While 500 lux is satisfactory for younger employees, the lighting requirement for older employees increases to 750 to 1,500 lux to avoid eye fatigue.

Legal Regulations and Standards:

DIN EN 12665 (ArbStättV) contains guidelines for the lighting of workplaces. It establishes criteria for a safe, healthy work environment, such as

Illuminance, Uniformity, and Glare Limitation.

The effects of inadequate workplace lighting can be serious. Poor lighting can negatively impact the health and performance of employees, thereby increasing error rates and accident risks.

HCL

Human Centric Lighting

Human Centric Lighting (HCL) focuses on the effect of lighting on people. It takes into account not only visible light but also ultraviolet and infrared radiation, which can trigger biological reactions in the body. Humans normally orient their daily rhythm to the sun. The so-called internal clock synchronizes with the presence or absence of sunlight. As our lifestyles increasingly change, however, it becomes increasingly difficult for the body to stay in balance.

Human Centric Lighting can be divided into 4 different categories:

Circadian Lighting: Is determined by the change of day and night as well as the seasons.

Activating Lighting: Serves to increase attention and activity.

Relaxing Lighting: Promotes relaxation and recovery.

Emotionally Appealing Lighting: Creates specific emotional moods.

What are the advantages of the HCL concept for indoor lighting?

  • Strengthens and supports the natural biorhythm
  • Can prevent sleep disorders
  • Promotes well-being, strengthens the immune system and thus health
  • Improves concentration and performance
  • Increases quality of life and vitality
Light in Old Age

Vision and Orientation in Old Age

To meet the needs of older people, it is advisable to upgrade the illuminance in the home. Experts recommend twice as high illuminance for seniors as for young people to achieve the same impression of brightness. The illuminance should be increased by at least one third above the usual standard values of 300 to 500 lux.

  • Light for seniors should always come from multiple sources. This way, a pleasant and balanced illumination and an even distribution of light in the room can be achieved.
  • This reduces shadows and dark corners and prevents glare. The light can be directed so that it does not shine directly into the users' eyes, which improves vision and reduces discomfort from overly bright light.
  • For a pleasant and functional environment, a mix of ceiling lights, light ceilings, wall, floor, or table lamps is suitable.
  • The even and contrast-free illumination of rooms ensures better orientation in old age and prevents falls.
  • Due to the natural fluctuations of daylight and seasonal light, indoor lighting should be dimmable to flexibly compensate for insufficient daylight. By dimming the lighting, a cozier atmosphere can also be created in the evening.
Melanopic Efficacy of Light

Light affects us in various ways: visually, emotionally, and biologically. The melanopic effect refers to the non-visual physiological effect of light on humans. The name comes from the hormone melanopsin, which makes people sleepy. Light can stimulate or suppress the production of this hormone; this process is then called the melanopic light effect. Already in earlier years, human life was determined by daylight. Today, light still determines the human sleep-wake rhythm and can be influenced thanks to new technologies. However, it is not the visual aspects of light that control our biorhythm.

The retinal ganglion cells of the eye Researchers found light-sensitive ganglion cells in the human retina. These receptors exclusively process non-visual, biological stimuli of light. The ganglion cells are responsible, among other things, for the release of the aforementioned melanopsin hormone and thus determine the circadian rhythm (24 hour rhythm).

The dynamics of the day-night cycle should also be replicated in artificial light control. Thus, a high blue component in light suppresses the release of melanopsin and thus promotes concentration and increases performance. A red component in light, on the other hand, increases the release of melanopsin and thus relaxes the body.

Spatial Distribution of Light The direction and spatial distribution of light also have an effect on our biorhythm, as a melanopic effect depends on the angle of incidence of the light. The retinal ganglion cells are located in the lower posterior part of the retina, which is why the light should reach our eyes broadly and diffusely from the upper half-space. Here, a connection to the natural light of the daytime sky is also recognizable. A particularly good biological effectiveness is achieved by large illuminated surfaces, e.g., light ceilings, which are reminiscent of the celestial canopy.

Light effect in old age With increasing age, not only does vision deteriorate, but less light also passes through the smaller pupils. For this reason, older people need more light than younger people. To achieve a melanopic effect in older people, almost four times more light is needed than in a young person. The relevance of proper lighting planning is enormous for stabilizing and strengthening the inner clock and the associated sleep-wake rhythm. By considering melanopic light, concentration, regeneration, mood, and emotions can be promoted and controlled.

PRIMEX – Competence in Lighting Technology

  • Experience & Manufacturing Competence: Development and production in Germany – supplemented by production partners in Europe and Asia for demand-oriented project solutions
  • Sustainable Production: Recycled aluminum profiles, water-based printing technology, resource-saving processes
  • Flexibility & Special Solutions: From individual frames to curved formats to complex light ceilings or special constructions
  • Comprehensive Service: Consulting, planning, construction, and logistics from a single source

Light is a design tool – PRIMEX makes it precisely usable. Whether retail, trade fair, architecture, or special construction – we deliver the lighting solution that works.

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