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Technical environment

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Ambient luminescence, focal glow and play of brilliants: lighting principles of lighting design

Ambient luminescence, focal glow and play of brilliants: explanatory project and mock-up images.

Ambient luminescence, focal glow and play of brilliants shown with example images.

Ambient luminescence, focal glow and play of brilliants are the three basic types of lighting in perception-oriented lighting design as developed by the American lighting designer Richard Kelly. This "grammar of light" not only forms an important basis for qualitative lighting design, but also for the development of luminaires.

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Overview on the topic

What is ambient luminescence?

Kelly names "ambient luminescence" as a first and basic form of light. This element provides general illumination of the surroundings. It ensures that the surrounding space, its objects and people in it are visible.

This type of lighting, which provides for general orientation and activity, largely coincides with the concepts of quantitative lighting design due to its wide-ranging, uniform character. Ambient luminescence however is not the goal, but merely the basis for more far-reaching lighting design. The aim is not to achieve blanket illumination of a supposedly optimal illuminance, but nuanced illumination that builds on the basic level of the ambient light.

What is focal glow?

To achieve this form of differentiation or nuancing, Kelly uses a second form of light which he calls "focal glow". Here, light is given the task of playing an active role in conveying information. This takes into account the fact that brightly lit areas involuntarily attract the viewer's attention.

The suitable distribution of brightness makes it possible to structure the wealth of information in an environment. Areas of essential information can be highlighted by emphasising the lighting, while lower-level or distracting information can be toned down by lowering the lighting level. This facilitates the fast and reliable communication of essential information. The visual environment, in its structures and in the meaning of its objects, is recognised. This applies equally to orientation in the room – e.g. quickly differentiating between a main entrance and a side entrance – and to the emphasis of objects, such as in merchandise displays or for highlighting the most valuable sculpture in a collection.

What is play of brilliants?

The third form of light, the "play of brilliants" results from the realisation that light can not only point to information, but is in itself information. This applies especially for brilliance effects caused by point light sources on reflective or refractive materials. However, the light source itself can also be perceived as brilliant.

Above all, play of brilliants gives life and atmosphere to prestigious rooms. What was traditionally achieved by chandeliers and candle flames can also be achieved in modern lighting design through the targeted use of light sculptures or by generating brilliance on illuminated materials.

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