Artificial lighting
ARTIFICIAL LIGHTING lecture notes
Dr. Habil. András Majoros
Figures, images and tables by Levente Filetóth
Budapest University of Technology and Economics
Faculty of Architecture
Department of Building Energetics and Services www.egt.bme.hu 2011.
Prof. András Majoros: Artificial Lighting – www.egt.bme.hu
1.
LIGHTING AND THE VISUAL ENVIRONMENT
THE COMPONENTS OF THE VISUAL ENVIRONMENT
The goal of lighting is to make the environment visible, the visual environment is a visible environment. The aim of lighting is to create an adequate visual environment.
The internal visual environment comes into being by illuminating a room. Thus, there are two components of the visual environment
- one is a usually furnished room with surfaces reflecting light to a greater or lesser extent , this is a basically passive component- and
- the other is light, which (as an active component) makes the room visible.
The surfaces of the interior can be characterized by their reflectance, while the use of light can be described by the illuminance of the surfaces.
LIGHT AND ITS QUALITY
Light is the visible part of the electromagnetic spectrum between the wavelengths of l = 380780 nm. Its symbol is Φ e, its unit is Watt [W]
Each wavelength corresponds to a given colour as shown in the following figure. Colours at shorter wavelengths are called cool (colours like purple and blue), colours at longer wavelengths are called warm colours (like orange and red).
We use so called white light for lighting, as the natural light that human vision developed by was white light, too.
It is a peculiarity of white light that it contains radiation at every wavelength of the visible range, and that the intensity of radiation at the different wavelengths vary to a certain extent. Thus, white light may vary. White lights differ from each other in colour combination, so white lights may differ in quality.
The quality of white light can be characterized with its spectral distribution.
There are two aspects of
Dr. Habil. András Majoros
Figures, images and tables by Levente Filetóth
Budapest University of Technology and Economics
Faculty of Architecture
Department of Building Energetics and Services www.egt.bme.hu 2011.
Prof. András Majoros: Artificial Lighting – www.egt.bme.hu
1.
LIGHTING AND THE VISUAL ENVIRONMENT
THE COMPONENTS OF THE VISUAL ENVIRONMENT
The goal of lighting is to make the environment visible, the visual environment is a visible environment. The aim of lighting is to create an adequate visual environment.
The internal visual environment comes into being by illuminating a room. Thus, there are two components of the visual environment
- one is a usually furnished room with surfaces reflecting light to a greater or lesser extent , this is a basically passive component- and
- the other is light, which (as an active component) makes the room visible.
The surfaces of the interior can be characterized by their reflectance, while the use of light can be described by the illuminance of the surfaces.
LIGHT AND ITS QUALITY
Light is the visible part of the electromagnetic spectrum between the wavelengths of l = 380780 nm. Its symbol is Φ e, its unit is Watt [W]
Each wavelength corresponds to a given colour as shown in the following figure. Colours at shorter wavelengths are called cool (colours like purple and blue), colours at longer wavelengths are called warm colours (like orange and red).
We use so called white light for lighting, as the natural light that human vision developed by was white light, too.
It is a peculiarity of white light that it contains radiation at every wavelength of the visible range, and that the intensity of radiation at the different wavelengths vary to a certain extent. Thus, white light may vary. White lights differ from each other in colour combination, so white lights may differ in quality.
The quality of white light can be characterized with its spectral distribution.
There are two aspects of