This report gives essential information necessary for consistent implementation of the CIE system for mesopic photometry (CIE 191:2010) in practical outdoor lighting applications. It describes how to calculate mesopic quantities according to the CIE system for mesopic photometry, including the method for calculating the adaptation coefficient, m. The adaptation field that should be used in these calculations is defined and background information to support this choice of adaptation field is presented. Visual tasks associated with outdoor lighting for drivers and pedestrians at night time are discussed and recommendations for those tasks for which the system is, and is not, applicable are presented.
The report emphasizes that mesopic luminous efficacy is not the only consideration when selecting light sources for installations in the mesopic range. Other important factors include: impacts on the natural environment, human health and well-being and colour rendering properties.
This findings in this report are especially important for those designing lighting for roads, cycle lanes and walking routes.
The document is written in English, with a short summary in French and German. It consists of 22 pages with one figure and is readily available from the CIE Webshop or from the National Committees of the CIE.
Members of a National Committee of the CIE receive a 66,7 % discount on the price, please approach your NC for information on accessing this discount.