Practical application of HDRI for discomfort glare assessment at indoor workplaces

Unified Glare Rating (UGR) is a measure of discomfort glare at indoor workplaces. Image luminance measuring device (ILMD), as an array photometer, makes it possible to measure the luminance distribution in the form of luminance map. It is the base for UGR calculation by an appropriate computer program. The range of measured luminance depends mainly on a glare source luminance, which often significantly exceeds the abilities of an array photometer sensor. High dynamic range (HDR) method, which is used in photography, can solve this problem partially. A practical approach to this problem was presented in the paper. A new procedure for preparing the set of photos for building HDR images was introduced. This effective method was developed to be used in UGR calculations. The use of the proposed procedure makes it possible to perform UGR measurements reliably, quickly, and efficiently, even by nonexperts in the field of lighting engineering. (C) 2019 The Author(s). Published by Elsevier Ltd.