## 5 Conclusions  
In the urban environment, artificial night light fulfils a dual purpose: functionality and aesthetics. It ensures the safety of users and enhances the visual appeal of public spaces, from ornate streetlights to illuminated architectural marvels. But as the article describes, finding the right balance between functional benefit and visual pleasure is not easy. Individual perceptions, cultural nuances, and context-specific requirements must be taken into account when designing lighting solutions. This discourse on outdoor lighting emphasizes a paradigm shift from purely objective measures of illumination to subjective interpretations of visual comfort that depend on the needs of the user in a particular environment. The introduction of the sustainability coefficient (Sn) represents an innovative approach to assessing lighting quality. By capturing the mood of the public in terms of perceived illumination likability versus illuminance intensity, the Sn provides a unique tool to assess the \"rightness\" of lighting in public spaces. The survey highlights the importance of lighting different urban facets, from focal points to wider public spaces. The feedback from 200 participants, students from the University of Maribor, offered insightful findings about their perceptions and values in relation to urban lighting. In light of the results, it is clear that while the need for lighting is unanimously recognized, the importance of lighting for different urban spaces and objects is perceived differently. These perceptions depend on specific needs, activities, and experiences. The empirical study focused on various urban typologies such as streets, squares, and parks. The sustainability coefficient (Sn) varied between the different locations, suggesting that individuals' perception of lighting is not uniform across urban environments. These variations could be due to different architectural features, the intended purposes of the spaces, or the environmental conditions. The subsequent phase of research aimed to confirm these observations. Using the SEC method (suitable for everyone, environmentally accepted, cost-effective) and SEC model, each site was analyzed for psychological, sociological, and aesthetic parameters. While most sites achieved consistently satisfactory results, there is a clear difference between outstanding sites and those in need of improvement. The SEC model proved invaluable in identifying these nuances. Applying the SEC methodology allowed for a comprehensive examination of the relationship between various factors and Sn. A key finding is that psychological and aesthetic-functional factors correlate moderately with Sn, while the sociological factors, particularly \"Usage Intensity\", show minimal correlation. However, on closer inspection, the study found that individual activities within the sociological factor, such as \"playing\" and \"sitting\", showed a strong positive correlation with Sn. This is related to [PERSON]'s theory [49], which categorizes activities and their potential relationships with the environment. The evaluation of individual locations revealed a range of scenarios resulting from the interplay between lighting intensity and aesthetic perception. These ranged from locations that needed a complete architectural overhaul to improve Sn to others that simply needed an adjustment in light intensity. This study makes several important contributions to the scientific understanding of urban lighting and its relationship to environmental comfort and human behavior:  
(1) Quantitative measurement with subjective components: In the study, the sustainability coefficient Sn is used as a quantifiable measure that includes two subjective components. Such measures provide a bridge between the quantitative and qualitative by providing objective metrics that nevertheless capture the nuances of human perception and experience.