At no point in our entire history of civilisation have we been able to create, curate and manipulate our living environment as we can now. From creating greenhouses in Antarctica to rainforests in deserts, today, technology allows us to create a built environment that meets our needs and desires. However, we often overlook the fact that this built environment not only influences our daily life, supporting our activities and functions, but also unconsciously affects our behaviour and emotions.

How light determines our perception of space

The built environment affects our physiological, cognitive, and psychological functions. The spaces and places created by the built environment are where we spend most of our lives, be it walking down a street, playing in the park, working in an office, or enjoying a cup of tea at home. A good experience in a particular place makes you remember it, feel attached to it, and improves your quality of life and satisfaction.

Similarly, light determines our perception of space—it enables us to experience the diverse qualities of the spaces: size, shape, texture, colour, and so on. Given that nearly 80% of all sensory perception is visual, light is the element with the greatest influence over the perception of a space. Therefore, good lighting design can enhance a space’s functionality and poetic and emotional impact.

For example, a luxurious living room with marble flooring and classical wall mouldings adorned with elegant furnishings and materials. A beautiful space, no doubt – now imagine this space with a red light at night. The luxurious room will transform into a scene resembling a horror movie. You wouldn’t be able to see any of the lavish, elegant furnishings or the sophisticated details, materials and textures. You would definitely not be pleased to talk to someone there or read a book.

See how a simple change in light can create or destroy a space’s function and emotional experience. This leads us to the question: How can we create the desired atmosphere with light?

Creating a desired atmosphere with lighting

To answer this question, we need to understand the effects of light and its role in influencing our visual perception.

Light defines our visual world by reflecting from one surface to another and scattering around. Once struck by illumination, a wall responds with specific effects depending on the quality and quantity of the light itself and the properties of its surface materials. Texture modifies its colour, and the angle at which light arrives alters its brightness, as does the viewing angle from which the wall is seen. One of the finest features of light is the shadows it creates, modelling and activating the surfaces around us. Visual perception occurs as the observer comes in contact with and interacts with the light from the visible surroundings.

Visual perception particularly responds to the following (along with cultural and social context):

• Brightness
• Contrast
• Colour
• Pattern

Understanding, manipulating, and controlling these characteristics can create a suitable visual environment. Knowledge of these focal accents and their power of attracting vision as people respond to the environment lies at the centre of creating a successful lighting design scheme.

Brightness

The phenomenon of brightness is fundamental to the experience of visual perception. The appearance of a given space is an individual opinion. It is, therefore, difficult to determine the right amount of brightness, as it is subjective and relative. For instance, just doubling the amount of light in space will not make it appear twice as bright. What is important is to increase the perceived brightness.

Our eyes can detect our surroundings over an extensive range of brightness, from moonlight to direct sunlight, by adjusting our pupils and controlling the amount of light entering the eye. However, there is a limitation, as we sometimes feel a lack of light even during the day or glare at night. The perception of brightness is influenced by many other factors—the reflectance of the room surfaces, the use of the space, and so on. Generally speaking, context plays a significant role, as do expectations.

Furthermore, brightness distributions in space provide information about our surrounding environment. They influence our behaviour, spatial perception and circumstances, connections, emotions, and mood. The brightness distribution makes spaces tangible and hence helps us experience architectural spaces.

A study by Flynn et al., 1973-1975

In a classic and often-cited study by Flynn et al., 1973-1975, a rectangular conference room was modified by different lighting combinations, including wall-washing (Indirect lighting) and downlighting (Direct lighting).

The findings discovered a brightness-spaciousness relationship, which is valuable for understanding the emotional impact of light. Indirect or reflected lighting conditions were given positive responses by the participants, including specific qualities of “pleasantness”, “harmonious”, “sociable” and “interesting”. Later studies also confirmed that rooms appear more spacious when illuminated by visible surfaces.

The creation of a clear, well-designed, and well-balanced lit environment is vital for spatial perception and psychological effects. The designer must understand and control the brightness distributions in space. They must be understood according to space, use, and users—when and which spatial boundaries can be emphasised and illuminated.

Contrast

Contrast can be explained as differences in luminance values. This difference allows us to recognise the three-dimensional form or texture of objects, and it is essential in an object-background relationship.

High contrast between the object and the background is often seen as dramatic, while low contrast can result in a uniform and flat appearance. We usually start differentiating objects from the background with a contrast ratio of 1:2 or 1:3. In museums and retail settings, the contrast difference between the displayed object and background can often be as high as 1:10 or 1:15, to highlight the objects and make them stand out.

Colour

The colour of light is produced by different wavelengths of light, from longer wavelengths of red to shorter wavelengths of blue, encompassing all the other colours between them. Experience that has been culturally and socially accumulated affects the colour of light emotionally. For example, red light is associated with fire and the sun and is read as a sign of warmth or warning.

When we look at the colour of an object, we are actually seeing only the reflected wavelengths from that object. For example, a red apple appears red because it reflects the red wavelength and absorbs the rest. As a result of this phenomenon, if you shine a red light on a blue object, it will appear black as the light does not contain the blue wavelength that makes the blue object appear blue.

The different wavelengths of light

White light is a combination of the different wavelengths of light. A simple experiment of passing sunlight through a prism reveals the colours of the rainbow it contains. The spectral distribution of light from various light sources defines the different wavelengths in the white light they create. For example, the spectral composition of sunlight contains all wavelengths. As a result, sunlight can render all the visible colours and is considered the benchmark to measure the colour rendering properties of all artificial light sources.

Different artificial light sources create light using various methods – for example, incandescent lamps produce light through filament heating. In contrast, LEDs produce light when electrons jump from positive to negatively charged surfaces in semiconductors. This difference in producing light creates a difference in the spectral composition of the light, i.e. the light is made up of different amounts of the visible wavelengths. Sunlight has a continuous spectral composition, whereas a fluorescent lamp, by comparison, will have a limited spectrum. Hence, white light is not always comprised of all the visible wavelengths. For this reason, care must be taken whilst using different light sources or in combination with daylight.

Pattern

The brain recognises patterns by its ability to understand similar forms as an image during the process of interpreting information through the eye. Our brains simplify complex patterns and geometries and look for patterns in compound images. The debate about beauty continues today, but we generally agree that where the pattern breaks down is a defect.

In regards to light, it can emphasise architectural patterns and destroy them. So, when installing lighting fixtures, you can create patterns with lighting fixtures or design them in harmony with the structure of the building.

Creating a suitable and appropriate visual environment

Until now, the narrative on the effects and role of light has been fragmented. We have tried to break down the characteristics and properties of light into elements to explain and analyse these effects better. However, the fact is that these effects in a real visual environment are far more complex and interactive.

Light distribution, intensity, direction, colour, brightness, contrast, and patterns all influence visual perception. These factors work with our cultural and sociological backgrounds to affect our emotions, create comfort, change our moods, and allow us to perform different functions. Therefore, in order to create a suitable visual environment, we need to understand and design the various aspects of light.

Contact our team of lighting design consultants for more information on creating the perfect visual environment with the right lighting.