Radiation characteristics

As the radiation characteristic, the directional light output of a luminaire is referred to, and depending on the light beam, it is distinguished between symmetrical and asymmetrical radiation characteristics. The radiation characteristic of a luminaire can be influenced by lenses, reflectors, baffles, or grids.

Symmetrical Emission Characteristic

A symmetrical radiation characteristic describes the uniform distribution of light in all directions within a certain beam angle. Here, a further distinction can be made between radially symmetrical and rotationally symmetrical radiation characteristics.

Radially Symmetrical

A radially symmetrical (also called spherically symmetrical) radiation characteristic can be imagined like a perfectly round sphere that radiates light in a uniform pattern. An example of this would be a light bulb. Whether one stands in front, behind, or to the side of the light source, the light is perceived equally from every angle. This feature is particularly useful in applications where uniform lighting is desired, such as in hallways or rooms that need to be fully illuminated.

Rotationally Symmetrical

In a rotationally symmetrical radiation characteristic, the light is radiated evenly around a central axis. This means that if you rotate the light source around this axis, the radiation pattern does not change. An example of this would be spotlights: such luminaires are often rotationally symmetrical because they emit light in a defined cone that is uniform around the central axis.

Asymmetrical Emission Characteristic

In an asymmetrical radiation characteristic, the light is not distributed evenly in all directions. Here, the light is directed toward specific areas, while other areas are less or not illuminated at all. This targeted light direction is often used to illuminate walls, pathways, or specific objects without overly brightening the surroundings. Typical examples include theater lighting, car headlights, or street lighting, where the light is primarily directed downwards and to the side to optimally illuminate the street without shining into the sky or unnecessarily onto surrounding buildings. Back