CIE Workshop on the Calculation and Measurement of Obtrusive Lighting

November 12, 2020 to November 13, 2020
Online with Zoom

Due to the current situation with the COVID-19 pandemic the workshop will now be held online. On the links below you can find updated information about registration and some other news. Please be patient as other important information is updated (including updates to the workshop information)

With the  change to an online workshop the registration fees have been reduced, practical demonstrations within the workshop have been extended and two CIE publications relevant to the workshop topic have been offered to the registered participants – one for free and one for  reduced price.  For those of you who previously registered, and paid, a refund will be made by the accounting department of the organizing team.

Looking forward to hearing from you and meeting you in the online space!


Please note that the dates may not have been updated on some documents!

Please note that the prorgmme will run from 10:00 to 17:00 (CET) on the first day and 09:00 to 17:30 (CET) on the second day


Event summary

Obtrusive light (also referred as light pollution) is a generic term for the adverse effects of artificial light on the night-time environment. Obtrusive light is a side effect of outdoor lighting installations, which is caused by inappropriate light distribution from luminaires and light reflected from illuminated surfaces. The origins of this side effect are due to improper design of lighting systems, a disregard for the needs of users and a lack of information on presence and movement of the users etc. Additionally, scattering in the atmosphere contributes heavily to the increase in sky glow especially when this is assisted by certain weather conditions. Rapid urbanization results increased quantity and concentration of artificial light at night and is leading to more and more obtrusive light which is uncontrolled in the environment. Obtrusive light hinders astronomic observations and has significant impact on the natural environment even at distant location.

While obtrusive light is an interdisciplinary problem, it is still mainly addressed within disciplines, leading to a fragmented knowledge base. For example, there has yet to be agreement over common language, metrics and measurement methods and instrumentation. The International Commission on Illumination (CIE), the international body for light and lighting, paves the way towards adaptive outdoor lighting where the visual needs of users are balanced against the negative impacts of obtrusive light. CIE has long recognised the importance of limiting obtrusive light and issued break-through guidelines on this subject.

The emergence of revolutionary lighting technologies in the last decade has however brought new challenges. This workshop aims to bring together professionals from different disciplines to discuss and outline future directions of investigation, modelling and calculation, measurement, research, development and standardization in the field of obtrusive light and light pollution.

This workshop will deal with the following topics around the issue of obtrusive lighting:

•   General aspects of the problem
•   Modelling and calculation methods and tools
•   Instrumentation and methods for the measurement and assessment
•   Temporal and spectral aspects
•   Environmental impact (humans, flora, fauna)
•   Outdoor lighting design methods and best practices

The CIE  and our hosts, VŠB - the Technical University of Ostrava, look forward to welcoming you to this workshop. The event will  include a session of practical measurements of obtrusive light when the road lighting system of an urban area will be turned on and off.  This practical demonstraion will be pre-recorded and presented as part of the workshop and made  avaialbe for viewing later by all who register for the workshop.

A big thanks to the Ostrava City Council for supporting this event.