Luminance describes the impression of brightness produced by a luminous or illuminated surface, measured in candelas per square meter (cd/m²). It relates the luminous intensity to the visible area of the light source.

Special feature of textile lightboxes: Unlike matte surfaces, translucent textiles do not reflect light—they transmit it. The resulting luminance is therefore determined by the illuminance (candela) multiplied by the fabric’s transmittance. This value determines how evenly and brilliantly your design glows from within.

Luminous flux indicates the total amount of light emitted by a light source, measured in lumens (lm). Unlike the power rating in watts, luminous flux takes into account the spectral sensitivity of the human eye and therefore describes how much light is actually perceived.

A higher luminous flux means greater perceived brightness—essential for evenly illuminating large-format displays and lightbox systems.

Luminous intensity describes how much luminous flux a source emits in a specific direction, measured in candela (cd). As a fundamental quantity in lighting technology (SI unit), all other photometric parameters are derived from it.

For directional applications such as spotlights or focused display lighting, luminous intensity is more relevant than total luminous flux because it describes the actual intensity in the desired emission direction.

Luminous efficacy indicates how many lumens a light source produces per watt of power consumed (lm/W). It is the key measure of energy efficiency: the higher the value, the more visible light is produced with the same electricity consumption.

Modern LED systems achieve values of 100–200 lm/W—a significant efficiency gain compared with conventional fluorescent tubes (60–100 lm/W). For trade show installations and retail displays operated continuously, this difference is clearly noticeable in annual energy consumption.

The lifespan of a light source is specified as an L70B50 value: the point at which 50% of the units have fallen below 70% of their original brightness. It is stated in operating hours (h).

High-quality LED systems achieve 50,000 h or more—which, with 12 hours of daily operation, corresponds to over 11 years. A longer lifespan reduces replacement and maintenance costs, making it a relevant factor in the total cost of ownership (TCO) of your display installations.

Illuminance describes how much luminous flux falls on a surface—measured in lux (lx), where 1 lx = 1 lm/m². It depends on location: it can be measured at any point on a surface, but decreases quadratically as the distance from the light source increases (inverse-square law).

In practice: Uniform illuminance across the entire display surface is the goal of every professional lightbox design—hotspots and dark edge areas occur when the distance between the light sources and the diffuser are not properly coordinated.

The LED (Light Emitting Diode) is a semiconductor device that converts electrical energy directly into light—without the detour through heat required by an incandescent bulb. When current flows through the diode, electrons and holes recombine at the semiconductor junction, emitting photons.

The color of the light depends on the semiconductor material used. Today, white LED light is produced primarily using blue LEDs with a yellow phosphor converter—or by combining red, green, and blue chips (RGB). RGB LEDs enable more than 16 million color combinations and form the basis for dynamic lighting installations and color-changing displays.

LEDs have become the dominant lighting technology in less than two decades—not through regulation alone, but because of their superior performance. The EU gradually banned the sale of incandescent bulbs completely by 2023; halogen lamps followed in 2018.

For architects, lighting designers, and display manufacturers, LED is now the standard technology—particularly because of its combination of energy efficiency, long service life, dimmability, and the ability to integrate with lighting management systems.

LED has established itself as the standard in modern lighting technology. Today, further development focuses primarily on three areas:

Intelligent control: Systems such as DALI 2 and Bluetooth Mesh enable daylight-dependent regulation and circadian lighting control—that is, adaptation to the human biological rhythm.

Compactness: Miniaturized LED chips (COB, SMD) allow for flatter designs and more uniform illumination—relevant for ultra-thin lightbox systems.

Efficiency: Peak values of over 200 lm/W have already been achieved in laboratories; commercial products currently reach 130–180 lm/W (as of 2024).

LEDs offer lighting planners and display designers a combination of flexibility and precision that no other light source can match.

Light quality: High-quality LEDs achieve color rendering indexes of Ra ≥ 95 and luminous efficacies of up to 180 lm/W. The point light source enables targeted beam control—lenses, reflectors, or diffusers can shape the light precisely without causing glare. Color temperatures from 2,700 K (warm white) to 6,500 K (daylight white) cover the full spectrum of visual requirements.

Lighting control: As electronic components, LEDs can be dimmed continuously and switched without delay. They can be seamlessly integrated into DALI, KNX, or smart home systems. This enables motion-activated lighting, scene control, and dynamic lighting transitions—without any loss of quality at low dimming levels.

The economic benefits of LED compared with conventional light sources are well documented today.

Service life: Professional LED modules achieve L70B50 values of 50,000 hours or more. At 12 hours of daily operation, this corresponds to over 11 years—with virtually no maintenance interruptions. After 50,000 hours, the remaining brightness is still at least 70% of the initial value.

Energy efficiency: Compared with an incandescent bulb, an LED uses approximately 80–90% less electricity for the same light output. Compared with fluorescent tubes, the savings are typically 40–60%. With luminous efficacies of 110–180 lm/W (depending on the product), LED is now the most efficient light source available on the mass market.

Operating costs: Since no wear parts such as starters or ballasts are required and lamp failures are rare exceptions, maintenance costs are largely eliminated—a significant advantage for hard-to-access installations or display systems operated continuously.

Light emission: The LED spectrum is limited to the visible range (380–780 nm). No UV or infrared radiation is emitted in significant amounts—protecting light-sensitive materials such as plastics, textiles, and printing inks from fading. For your textile lightboxes with high-quality printed designs, this is a practical advantage.

Recycling: LEDs contain no mercury, unlike fluorescent tubes and energy-saving lamps, which must be disposed of as hazardous waste. You can return them through the regular electrical waste recycling system (ElektroG).

CO₂ footprint: The significantly reduced electricity consumption directly impacts operational emissions. In a typical 10-lightbox setup operated for 5 years, the electricity savings compared with fluorescent tubes can amount to several tonnes of CO₂ equivalent, depending on the electricity mix.

Light is the decisive factor in visual perception—and therefore in the impact of every display, trade fair installation, and retail environment. Without adequate lighting, even the highest-quality printed graphic loses its impact: contrasts become flatter, colors appear dull, and details disappear.

This is precisely where the key advantage of backlit lightbox systems lies: the graphic glows from within and is actively perceived—even in bright ambient light at trade fairs or in shop windows. The human eye responds more strongly to self-luminous surfaces than to reflective ones—an effect that advertising psychology has deliberately leveraged for decades.

Light color describes the inherent color of the light emitted by a light source—that is, whether it appears more yellowish and warm or cool and bluish. It is measured in kelvins (K) using the so-called color temperature.

The Planckian radiator (also known as a blackbody) serves as the physical reference value—an idealized object that does not reflect light but emits it itself when heated. The color spectrum it passes through—from red via orange and yellow to white and finally light blue—defines the Kelvin scale. The higher the temperature, the cooler and bluer the light.

For lightbox systems and display lighting, choosing the right light color is crucial: It affects how printed colors are perceived, how natural skin tones appear, and whether a trade fair stand feels inviting or sterile.

Color temperature is divided into three practically relevant ranges:

Warm white (< 3,300 K)
Yellowish, warm light reminiscent of candlelight or sunset. It creates an inviting and cozy atmosphere—preferred in retail, hospitality, and emotionally engaging brand presentations. The right choice for lightboxes featuring warm visual themes (lifestyle, food, interior design).

Neutral white (3,300–5,300 K)
Balanced, matter-of-fact light without a dominant color cast. Suitable for work environments, trade shows, and technical presentations where color accuracy is more important than atmosphere.

Daylight white (> 5,300 K)
Cool, bluish-white light that corresponds to natural daylight. It promotes alertness and concentration (well supported by research on circadian light, including Cajochen et al., 2000). Suitable for displays where maximum brightness and color brilliance are the priorities.