Lighting refers to the strategic use of light and fixtures to achieve practical or aesthetic effects. It can involve natural sources, such as sunlight, skylights, or reflections, as well as artificial sources like lamps, LED fixtures, and other luminaires. Technically, light is the part of the electromagnetic spectrum that our eyes can perceive, with a wavelength range between 380 and 780 nm. During the day, humans perceive colors, while at night, vision is limited to shades of gray.
Daylighting—using windows, skylights, or light shelves—is often utilized as the main source of illumination during daytime. This not only enhances visual comfort but also reduces energy consumption, as artificial lighting is a major component of building energy use. Proper lighting can improve task performance, highlight architectural features, and positively affect mood and productivity.
Indoor lighting is a key part of interior design, while outdoor lighting plays an important role in landscape projects. Lighting designers are responsible for designing, installing, and managing lighting systems to achieve the best efficiency and aesthetic effect.
Effects of lighting
Visual functions - Biological effects - Emotional perception
Lighting has three main effects
- Light for visual functions
- Illuminates task areas according to relevant standards.
- Ensures glare-free and convenient conditions.
- Light for Biological Effects
- Supports circadian rhythms.
- Can stimulate or relax occupants depending on intensity and color.
- Light for Emotional Perception
- Enhances architectural features
- Creates attractive scenes and ambiance
Basic parameters of lighting Luminous flux – Luminous intensity – Illuminance – Luminance
1. Luminous flux (Φ )
The luminous flux represents the total amount of light emitted by a light source. Meanwhile, luminous efficiency measures how effectively a light source converts electrical power into visible light and is calculated as the ratio of luminous flux to electrical power consumed (lm/W). This metric serves as an indicator of the light source’s energy and economic efficiency.
Abbreviation: Φ Phi
Unit: lm Lumen
2. Luminous intensity (I)
Luminous intensity describes the amount of light emitted in a specific direction. This measurement is particularly useful for directional lighting elements, such as reflectors. Additionally, it is commonly represented using a luminous intensity distribution curve (LDC), which visually illustrates how light is distributed from the source.
Abbreviation: I
Unit: cd Candela
3. Illuminance (E)
Illuminance describes the quantity of luminous flux falling on a surface. It decreases by the square of the distance (inverse square law). Relevant standards specify the required illuminance (e.g. EN 12464 “Lighting of indoor workplaces”).
Illuminance: E(lx) = luminous flux (lm)/area (m2)
Abbreviation: E
Unit: lx Lux
4. Luminance (L)
Luminance is the only basic lighting parameter that is perceived by the eye. It specifies the brightness of a surface and is essentially dependent on its reflectance (finish and color).
Abbreviation: L
Unit: cd/m2
Types of lighting
Direct lighting - Indirect lighting - Direct /indirect lighting - Mellow lighting
Direct Lighting
– Highly directional
– Strong glare reduction at certain angles
– Dark ceiling (cave effect)
– Limited flexibility of workstation layout
– Energy efficiency on the task level
Indirect Lighting
– Diffuse lighting conditions
– Room gains in height
– Glare-free
– Workstations can be positioned anywhere
– Low energy efficiency
Direct / Indirect Lighting
– Pleasant room impression
– High user acceptance
– Good contrast ratios
– Flexible workstation layout
(indirect component > 60 %)
Mellow Light
– Recessed direct/indirect solution
– Workstations can be positioned anywhere
– Glare-free
– Reduced luminance levels at all viewing angles
– Gives an impression of daylight in room
Layers of lighting
Ambient lighting - Accent lighting - Task lighting - Feature lighting
Ambient Lighting
Ambient lighting, also known as general lighting, illuminates a room evenly and provides a consistent level of brightness throughout the space, regardless of other light sources. In addition to creating a well-lit environment, it ensures safe and comfortable movement within the room. By bouncing off walls and ceilings, ambient light helps fill the space effectively, giving the room a balanced and inviting atmosphere.
Accent Lighting
Accent lighting is designed to draw attention to specific points of interest or to create a desired visual effect. It can make a room appear larger while highlighting key elements such as architectural features, artwork, sculptures, plants in outdoor layouts, or curated collections. By adding depth and contrast, accent lighting enhances the overall ambiance and adds character to any space.
Task Lighting
Task lighting provides focused illumination for activities performed in a specific area, such as reading, cooking, or working on a computer. This type of lighting requires a brighter, concentrated light to ensure clarity and precision. To create a comfortable and effective workspace, it is best to avoid harsh lighting or shadows that may cause eye strain or visual discomfort.
Feature Lighting
Feature lighting adds personality and character to a space, making it visually distinctive. This type of lighting often highlights the fixture itself, creating a statement whether it is turned on or off. For example, a pendant light positioned at the center of a bedroom can enhance comfort and make the space feel cozier. Choosing a pendant with a soft, diffuse design that complements your table or floor lamps can create a harmonious and inviting atmosphere
FAQ about lighting definition, basics & types
What does lighting mean?
What are the 3 types of lighting?
What is importance of lighting?
What are effects of lighting?
Light creating biological effects by supporting people’s circadian rhythm for stimulating or relaxing mood.
Light for emotional perception Lighting enhancing architecture by creating scenes and effects
