International Journal of Sustainable Lighting <p><strong>Introduction</strong></p> <p>The International Journal of Sustainable Lighting (IJSL) is the successor of the former Ingineria Iluminatului - Journal of Lighting Engineering, issued in Romania starting with 1999. IJSL aims to become an internationally recognized journal and to complement the existing prestigious lighting journals with an emphasis on emerging lighting issues including light pollution, chronobiology, sustainable buildings by extending its readers and authors to the worldwide lighting communities. The IJSL is an open access journal and is published bi-annaully in June, and December each year.</p> <p><strong>Aims and Scope</strong></p> <p>The International Journal of Sustainable Lighting is based on a change of paradigm from energy-efficiency to trans-disciplinarity (including energy, ecology, biology, green buildings, astronomy); it is a peer reviewed scientific journal encompassing experimental, theoretical and applied research results with respect to field of sustainable lighting. It provides a forum for architects, engineers, biologists and researchers involved in the design, operation, construction and utilization of lighting.</p> <p>The foremost objective is to give a quality online publication to our readers and authors. In this pursuit, our effort focuses upon quality publishing and an unquestioned commitment to the highest standards of professional and corporate ethics.</p> <p><strong>Editors-in-Chief</strong></p> <p>Jeong Tai Kim, Professor, Kyung Hee University, Republic of Korea</p> <p>Dorin Beu, Professor, Technical University of Cluj-Napoca, Romania</p> <p><strong>Executive Editor</strong></p> <p>Geun Young Yun, Associate Professor, Kyung Hee University, Republic of Korea</p> <p>&nbsp;</p> <p>&nbsp;</p> International Journal of Sustainable Lighting en-US International Journal of Sustainable Lighting 2586-1247 <p>All International Journal of Sustainable Lighting (IJSL) content is Open Access, meaning it is accessible online without fee under the terms of the Creative Commons Attribution License ( &nbsp;For any reuse, redistribution, or reproduction of a work, users must clarify the license terms under which the work was produced. Neither the text itself nor the ideas presented in it may be used for commercial purposes.</p> Performance of different metrics proposed to CIE TC 1-91 <p>The main aim of the article is to find out the performance of different metrics proposed to CIE TC 1-91. Currently, six different indexes have been proposed to CIE TC 1-91: Colour Quality Scale (CQS), Feeling of Contrast Index (FCI), Memory colour rendering index (MCRI), Preference of skin (PS), Relative gamut area index (RGAI) and Illuminating Engineering society Method for evaluating light source colour rendition (IES TM-30). The evaluation and analysis are based on previously conducted experiment in lighting booth. The analysis showed the area based metric FCI was good subjective preference indicator. The subjective preference was measured in terms of naturalness of objects, colourfulness of colour checker chart, and the visual appearance of the lit scene in the booth.</p> Pramod Bhusal Rajendra Dangol Copyright (c) 2017 Pramod Bhusal, Rajendra Dangol 2017-12-29 2017-12-29 19 2 91 91 10.26607/ijsl.v19i2.36 Variations on a classical theme: On the formal relationship between magnitudes per square arcsecond and luminance <p>The formal link between magnitudes per square arcsecond and luminance is discussed in this paper. Directly related to the human visual system, luminance is defined in terms of the spectral radiance of the source, weighted by the CIE V(l) luminous efficiency function, and scaled by the 683 lm/W luminous efficacy constant. In consequence, any exact and spectrum-independent relationship between luminance and magnitudes per square arcsecond requires that the last ones be measured precisely in the CIE V(l) band. The luminance value corresponding to m<sub>VC</sub>=0 (zero-point of the CIE V(l) magnitude scale) depends on the reference source chosen for the definition of the magnitude system. Using absolute AB magnitudes, the zero point luminance of the CIE V(l) photometric band is 10.96 x 10<sup>4 </sup>cd·m<sup>-</sup><sup>2</sup>.</p> Salvador Bará Copyright (c) 2017 Salvador Bará 2017-12-29 2017-12-29 19 2 104 104 10.26607/ijsl.v19i2.77 Changes in outdoor lighting in Germany from 2012-2016 <p>Changes in the total lit area and the radiance of stably lit area in the German federal states from 2012-2016 were investigated using the Day-Night Band of the Visible Infrared Imaging Radiometer Suite. Most states increased in both lit area and radiance. The lit area of Bayern and Schleswig-Holstein grew rapidly, at annual rates of 9.7% and 8.8% respectively. Thüringen was dramatically different from the other states, with a 4.5% annual decrease in lit area, and a 17% annual decrease in the radiance of stably lit areas. In at least some cases, the increases in lighting in Bayern area associated with transitions to LEDs, which may not be indicative of a transition towards sustainable lighting. In addition to these results, this paper discusses the role of remotely sensed nighttime data within the context of sustainable lighting.</p> Christopher C. M. Kyba Theres Kuester Helga U Kuechly Copyright (c) 2017 Christopher C. M. Kyba, Theres Kuester, Helga U Kuechly 2017-12-29 2017-12-29 19 2 112 112 10.26607/ijsl.v19i2.79 Light Guide Collector Prototype: Laboratory Testing <p>The article reviews the potential of light guide system equipped by a concentrator device capturing daylight applicable for illumination of building interiors and presents results of experiments on performance of its prototype. The main goal is focused on the comparison of traditional solutions and newly developed prototype of the light guide system and presents examination of its light transmission efficiency based on the laboratory experiments.</p> Jitka - Mohelnikova Stanislav Darula Ayodeji Omishore Petr Mohelnik Denis Micek Copyright (c) 2017 Jitka - Mohelnikova, Stanislav Darula, Ayodeji Omishore, Petr Mohelnik, Denis Micek 2017-12-29 2017-12-29 19 2 124 124 10.26607/ijsl.v19i2.81 A shining example of sustainable church lighting using the EcoSky LED: 96% reduction in energy consumption, and dramatic reduction of light pollution. <p>The lighting of the Church of the Three Kings in Logatec, Slovenia was replaced in 2014. The power of the installation was reduced 96% from 1.6 kW to 58 W, and spill light from the site was effectively eliminated. As a result, the church is no longer visible in nighttime satellite images of the area, indicating a reduction of waste light from the site of at least a factor of 30. This article discusses the concept of sustainability with regards to cultural heritage lighting, within the context of this example.</p> Christopher C. M. Kyba Andrej Mohar Gašper Pintar Jurij Stare Copyright (c) 2017 Christopher C. M. Kyba, Andrej Mohar, Gašper Pintar, Jurij Stare 2018-02-20 2018-02-20 19 2 132 132 10.26607/ijsl.v19i2.80