Dark sky and light pollution

Flora and fauna face challenges from artificial light during the night, and stars are no longer visible in various regions of the night sky. Emlyn Etienne Goronczy, a lighting designer at Studio DL, a successful European planning office with branches in Hanover, Stuttgart, Amsterdam and Warsaw, specializes in preventing light pollution. He shared his expertise with us during a presentation at the TRILUX Academy, among other occasions. For those who missed the event, we asked for further insights.

Why is it important to consider light pollution in lighting design?

Light pollution is an important social issue today. For example, it can affect human health, by disrupting the natural biorhythm. However, people can determine the light dose themselves and thus protect themselves to a certain extent from too much light. In addition, evening activities such as watching TV or playing sports influence people's biorhythms more than outdoor lighting.

Are there any types of luminaires that you recommend for protecting the night sky?

This cannot be answered in general terms but only on a project-specific basis. A country road without façades on the sides lacks vertical absorption surfaces. In this case, the right solution may be a Full Cut Off luminaire (ULOR 0 luminaires) that provides precisely directed light exclusively onto the roadway. This would again be the wrong approach for an urban environment where vertical illuminance levels are also required for facial recognition (for a sense of safety, quality of stay, etc.).

Basically, I think it is important to keep illuminance levels as low as possible and to have controllable and dimmable luminaires. In this sense, lighting management is a key component in achieving Dark Sky goals.

In your opinion, what is the ideal balance between safety through lighting and protecting the night sky?

Here, too, there is no universal blueprint. Good lighting is always planned on a site-specific and interdisciplinary basis. The area-specific project requirements are defined at the beginning. These include the needs of society, such as the feeling of safety and the quality of stay, as well as the needs of the ecosystem. This is followed by an interdisciplinary analysis of the site by architects, urban planners, biologists and lighting designers. They weigh up the various needs and balance them on a project-specific basis. The result is, therefore, always a compromise.