Pub Date : 2023-05-20DOI: 10.1177/14771535231172084
M. Alwalidi, A. Ganji Kheybari, S. Subramaniam, S. Hoffmann
The spectral composition of light has been linked to various non-image-forming responses besides visual photoreception. Accordingly, simulation tools must incorporate the spectral composition of light to account for such responses. A simulation tool was developed which uses N-step algorithm and subdivides the (red, green, and blue) RGB bands into multiple channels. This research intends to validate the tool for different lighting scenarios. A physical model was constructed in which the integral irradiance from 380 nm to 780 nm was measured for three scenarios: diffuse daylight, electric light with variable correlated colour temperature and a combination of both. All three scenarios were simulated with 3, 9, 27 and 81 channels. For scenarios with electric light and combination of daylight and electric light, the nine-channel simulation improved the mean absolute percentage error (MAPE) by 13.9% to 33.9% compared to the three-channel simulation. For continuous daylight, there was only a small improvement of 0.4% when increasing from 3 to 27 channels. In comparison to 9 channels, 27 channels slightly improved MAPE in all the scenarios but substantially increased the simulation time. Increasing the number of channels to 81 is likelier to bring a contribution to more complex scenarios than that presented in this study.
{"title":"Development of a multichannel spectral simulation tool and experimental validation with different lighting scenarios","authors":"M. Alwalidi, A. Ganji Kheybari, S. Subramaniam, S. Hoffmann","doi":"10.1177/14771535231172084","DOIUrl":"https://doi.org/10.1177/14771535231172084","url":null,"abstract":"The spectral composition of light has been linked to various non-image-forming responses besides visual photoreception. Accordingly, simulation tools must incorporate the spectral composition of light to account for such responses. A simulation tool was developed which uses N-step algorithm and subdivides the (red, green, and blue) RGB bands into multiple channels. This research intends to validate the tool for different lighting scenarios. A physical model was constructed in which the integral irradiance from 380 nm to 780 nm was measured for three scenarios: diffuse daylight, electric light with variable correlated colour temperature and a combination of both. All three scenarios were simulated with 3, 9, 27 and 81 channels. For scenarios with electric light and combination of daylight and electric light, the nine-channel simulation improved the mean absolute percentage error (MAPE) by 13.9% to 33.9% compared to the three-channel simulation. For continuous daylight, there was only a small improvement of 0.4% when increasing from 3 to 27 channels. In comparison to 9 channels, 27 channels slightly improved MAPE in all the scenarios but substantially increased the simulation time. Increasing the number of channels to 81 is likelier to bring a contribution to more complex scenarios than that presented in this study.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122925318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-19DOI: 10.1177/14771535231170500
SL Hartmeyer, M. Andersen
Light dosimetry aims to measure personal light exposure with wearable sensors, which is a complex multistep procedure. The resulting data may be used to investigate non-visual effects of light in real-life settings, to validate laboratory findings and answer questions pertaining to implications in applied contexts. However, personal light exposure patterns are usually complex and can be quantified in many ways. Various measurement and analysis methods have been applied across previous studies, complicating comparability and interpretation of results. To improve the quality and comparability of light-dosimetry research, a framework with consensus guidelines for light-dosimetry procedures is needed. To provide the groundwork towards such a framework, we reviewed previous light-dosimetry studies to identify considerations regarding measurement and data quantification. Here, we review metrics for quantifying light-dosimetry data in terms of the characteristics known to modulate non-visual responses. Overall, various metrics have been employed across studies, with several metrics for each characteristic. We provide a description of each metric, discuss their properties and provide example calculations for the application to light-dosimetry data. Moreover, we propose considerations for data quantification and possible research strategies for future studies. To facilitate exploration and use of the identified metrics, corresponding functions are provided in an openly accessible R-package.
{"title":"Towards a framework for light-dosimetry studies: Quantification metrics","authors":"SL Hartmeyer, M. Andersen","doi":"10.1177/14771535231170500","DOIUrl":"https://doi.org/10.1177/14771535231170500","url":null,"abstract":"Light dosimetry aims to measure personal light exposure with wearable sensors, which is a complex multistep procedure. The resulting data may be used to investigate non-visual effects of light in real-life settings, to validate laboratory findings and answer questions pertaining to implications in applied contexts. However, personal light exposure patterns are usually complex and can be quantified in many ways. Various measurement and analysis methods have been applied across previous studies, complicating comparability and interpretation of results. To improve the quality and comparability of light-dosimetry research, a framework with consensus guidelines for light-dosimetry procedures is needed. To provide the groundwork towards such a framework, we reviewed previous light-dosimetry studies to identify considerations regarding measurement and data quantification. Here, we review metrics for quantifying light-dosimetry data in terms of the characteristics known to modulate non-visual responses. Overall, various metrics have been employed across studies, with several metrics for each characteristic. We provide a description of each metric, discuss their properties and provide example calculations for the application to light-dosimetry data. Moreover, we propose considerations for data quantification and possible research strategies for future studies. To facilitate exploration and use of the identified metrics, corresponding functions are provided in an openly accessible R-package.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127603108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-17DOI: 10.1177/14771535231162505
B. Abboushi, S. Fotios, N. Miller
After dark, pedestrians may experience discomfort from glare caused by outdoor lighting. While several models for measuring discomfort have been proposed, there is no consensus as to which model should be used. The performances of different models were investigated using datasets from four independent studies, comparing the degree of association between model predictions and subjective ratings, and the ability of a model to distinguish between discomfort and non-discomfort situations. The models tested are those proposed by Petherbridge and Hopkinson in 1950, Schmidt-Clausen and Bindels in 1974, Bullough et al. in 2008 and Lin et al. in 2014 and 2015. They also include two quantities: direct illuminance at the eye from the glare source and average source luminance. Of the models tested, the best performance was found using either the model proposed by Bullough et al. in 2008 or by direct illuminance at the eye.
{"title":"Predicting discomfort from glare with pedestrian-scale lighting: A comparison of candidate models using four independent datasets","authors":"B. Abboushi, S. Fotios, N. Miller","doi":"10.1177/14771535231162505","DOIUrl":"https://doi.org/10.1177/14771535231162505","url":null,"abstract":"After dark, pedestrians may experience discomfort from glare caused by outdoor lighting. While several models for measuring discomfort have been proposed, there is no consensus as to which model should be used. The performances of different models were investigated using datasets from four independent studies, comparing the degree of association between model predictions and subjective ratings, and the ability of a model to distinguish between discomfort and non-discomfort situations. The models tested are those proposed by Petherbridge and Hopkinson in 1950, Schmidt-Clausen and Bindels in 1974, Bullough et al. in 2008 and Lin et al. in 2014 and 2015. They also include two quantities: direct illuminance at the eye from the glare source and average source luminance. Of the models tested, the best performance was found using either the model proposed by Bullough et al. in 2008 or by direct illuminance at the eye.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124783700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-06DOI: 10.1177/14771535231165263
J. Xu, M. Liu, L. Li, Z. Xia
A field study was conducted in two classrooms to explore the effects of standard and high light levels on sleep, alertness and mood of boarding high school students in Suzhou, China. 79 participants took part in a 7-week study in winter. After 3-week baseline assessments under standard lighting, participants were exposed to 3-week high light levels, separated by a 1-week washout. One group experienced this condition in the morning and the other experienced it in the evening. Horizontal illuminance was recorded in real time during the experiment and converted to eye-level vertical illuminance and equivalent melanopic lux. Sleep wristbands and questionnaires were used. Morning or evening high light levels significantly improved acute alertness during the increased light level hours compared with standard lighting, but there was no significant difference in sleep or mood. Additionally, compared to the evening high light levels, morning condition was significantly associated with longer deep sleep duration, easier falling asleep and lower negative mood. This study is the first to directly correlate high light conditions and timing of light exposure with subjective and objective sleep, alertness and mood of Chinese boarding high school students, which can provide references for the application of healthy lighting in classrooms.
{"title":"Effects of environmental lighting on students’ sleep, alertness and mood: A field study in a Chinese boarding school","authors":"J. Xu, M. Liu, L. Li, Z. Xia","doi":"10.1177/14771535231165263","DOIUrl":"https://doi.org/10.1177/14771535231165263","url":null,"abstract":"A field study was conducted in two classrooms to explore the effects of standard and high light levels on sleep, alertness and mood of boarding high school students in Suzhou, China. 79 participants took part in a 7-week study in winter. After 3-week baseline assessments under standard lighting, participants were exposed to 3-week high light levels, separated by a 1-week washout. One group experienced this condition in the morning and the other experienced it in the evening. Horizontal illuminance was recorded in real time during the experiment and converted to eye-level vertical illuminance and equivalent melanopic lux. Sleep wristbands and questionnaires were used. Morning or evening high light levels significantly improved acute alertness during the increased light level hours compared with standard lighting, but there was no significant difference in sleep or mood. Additionally, compared to the evening high light levels, morning condition was significantly associated with longer deep sleep duration, easier falling asleep and lower negative mood. This study is the first to directly correlate high light conditions and timing of light exposure with subjective and objective sleep, alertness and mood of Chinese boarding high school students, which can provide references for the application of healthy lighting in classrooms.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124827119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-14DOI: 10.1177/14771535231158029
H. Rolf, L. Udovičić, S. Völker
Since the proportion of digital and more flexible work in the western labour market increases, more and more employees are working at least partly from home. This development was even enhanced by the COVID-19-pandemic. In contrast to office workplaces, lighting at home-based workplaces is less studied and regulated. Lighting has been shown to not only ensure vision but also evoke non-image forming effects such as changes in alertness. In this study, light exposure of nine office employees at their home-based workplaces was investigated. Illuminance at home-based workplaces was found to be low, compared to office standards. In addition, melanopic equivalent daylight illuminance (MEDI) did not reach recommendations for healthy daytime light exposure. Furthermore, an additional lighting was installed at participants’ desks in order to examine possible effects on alertness. Mean illuminance and MEDI during work were increased by the additional lighting. A decrease in subjective sleepiness could be shown after 6 hours, although differences were not significant. Improvements of response time in a psychomotor vigilance task were already achieved at the beginning of work and after 3 hours. This study shows that lighting conditions at home-based workplaces often do not meet the criteria for health-promoting lighting in terms of non-image forming effects.
{"title":"Light exposure in home-based work: Can a simple lighting system increase alertness?","authors":"H. Rolf, L. Udovičić, S. Völker","doi":"10.1177/14771535231158029","DOIUrl":"https://doi.org/10.1177/14771535231158029","url":null,"abstract":"Since the proportion of digital and more flexible work in the western labour market increases, more and more employees are working at least partly from home. This development was even enhanced by the COVID-19-pandemic. In contrast to office workplaces, lighting at home-based workplaces is less studied and regulated. Lighting has been shown to not only ensure vision but also evoke non-image forming effects such as changes in alertness. In this study, light exposure of nine office employees at their home-based workplaces was investigated. Illuminance at home-based workplaces was found to be low, compared to office standards. In addition, melanopic equivalent daylight illuminance (MEDI) did not reach recommendations for healthy daytime light exposure. Furthermore, an additional lighting was installed at participants’ desks in order to examine possible effects on alertness. Mean illuminance and MEDI during work were increased by the additional lighting. A decrease in subjective sleepiness could be shown after 6 hours, although differences were not significant. Improvements of response time in a psychomotor vigilance task were already achieved at the beginning of work and after 3 hours. This study shows that lighting conditions at home-based workplaces often do not meet the criteria for health-promoting lighting in terms of non-image forming effects.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"249 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114339895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-14DOI: 10.1177/14771535231158078
R. Xu, H. Ye, B. Hu, S. Jin, M. Lu, Z. Huang, L. Chen
To achieve energy saving and safe driving in a tunnel, this work proposes a tunnel intelligent dimming control and energy consumption monitoring system. Firstly, a dynamic predicted tunnel traffic volume is established to optimize the timeliness of the system tunnel traffic volume. Secondly, a backpropagation neural network-based dimming control model is constructed, in which the luminance outside the tunnel, traffic volume and vehicle speed serve as the input, and the luminance inside the tunnel is the output. This model is then combined with the established integrated closed-loop control model of the tunnel internal and external luminance to achieve continuous dimming control of the tunnel. Finally, an energy consumption monitoring system is designed with an energy monitoring unit. The designed system was implemented and tested for 63 days in the Yongtaiwen–Chayuanli (China) tunnel. Experiment results show that the designed system can automatically control the luminance of the tunnel lighting according to the luminance measured outside the tunnel, traffic volume and vehicle speed, thus achieving continuous dimming control. This significantly reduced the power consumption (by approximately 65%) whilst ensuring the safety of tunnel traffic.
{"title":"Intelligent dimming control and energy consumption monitoring system of tunnel lighting","authors":"R. Xu, H. Ye, B. Hu, S. Jin, M. Lu, Z. Huang, L. Chen","doi":"10.1177/14771535231158078","DOIUrl":"https://doi.org/10.1177/14771535231158078","url":null,"abstract":"To achieve energy saving and safe driving in a tunnel, this work proposes a tunnel intelligent dimming control and energy consumption monitoring system. Firstly, a dynamic predicted tunnel traffic volume is established to optimize the timeliness of the system tunnel traffic volume. Secondly, a backpropagation neural network-based dimming control model is constructed, in which the luminance outside the tunnel, traffic volume and vehicle speed serve as the input, and the luminance inside the tunnel is the output. This model is then combined with the established integrated closed-loop control model of the tunnel internal and external luminance to achieve continuous dimming control of the tunnel. Finally, an energy consumption monitoring system is designed with an energy monitoring unit. The designed system was implemented and tested for 63 days in the Yongtaiwen–Chayuanli (China) tunnel. Experiment results show that the designed system can automatically control the luminance of the tunnel lighting according to the luminance measured outside the tunnel, traffic volume and vehicle speed, thus achieving continuous dimming control. This significantly reduced the power consumption (by approximately 65%) whilst ensuring the safety of tunnel traffic.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130557097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-07DOI: 10.1177/14771535231156617
L. Flores-Villa, T. Oberman, C. Guattari, F. Asdrubali, M. Frascarolo, GE Puglisi, A. Astolfi, F. Aletta
Recently, there has been a growing interest to implement a holistic approach to study perception in urban settings with historic value, in which environmental factors such as acoustics and lighting play an important role. However, little research has addressed sound and light in combination. In this exploratory field study, a soundscape and lightscape protocol was implemented to gather both objective and subjective data. In all, 46 people joined a group walk around the historical sites of Colosseum and Fori Imperiali in Rome. Participants assessed the soundscape and lightscape quality via questionnaire at four locations, immediately before and after the sunset in April 2021. Acoustic parameters (A-weighted equivalent sound level, loudness, sharpness, roughness) and lighting parameters (luminance, colour rendering index and correlated colour temperature) were measured at each location while participants filled in the questionnaire. While there was little variation in the acoustic parameters measured before and after the sunset walks, changes were observed in perceptual data about the soundscape. These outcomes reveal a potential effect of lighting conditions on soundscape perception.
{"title":"Exploring relationships between soundscape and lightscape perception: A case study around the Colosseum and Fori Imperiali in Rome","authors":"L. Flores-Villa, T. Oberman, C. Guattari, F. Asdrubali, M. Frascarolo, GE Puglisi, A. Astolfi, F. Aletta","doi":"10.1177/14771535231156617","DOIUrl":"https://doi.org/10.1177/14771535231156617","url":null,"abstract":"Recently, there has been a growing interest to implement a holistic approach to study perception in urban settings with historic value, in which environmental factors such as acoustics and lighting play an important role. However, little research has addressed sound and light in combination. In this exploratory field study, a soundscape and lightscape protocol was implemented to gather both objective and subjective data. In all, 46 people joined a group walk around the historical sites of Colosseum and Fori Imperiali in Rome. Participants assessed the soundscape and lightscape quality via questionnaire at four locations, immediately before and after the sunset in April 2021. Acoustic parameters (A-weighted equivalent sound level, loudness, sharpness, roughness) and lighting parameters (luminance, colour rendering index and correlated colour temperature) were measured at each location while participants filled in the questionnaire. While there was little variation in the acoustic parameters measured before and after the sunset walks, changes were observed in perceptual data about the soundscape. These outcomes reveal a potential effect of lighting conditions on soundscape perception.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116037646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-25DOI: 10.1177/14771535231154479
L. Van de Perre, K. Smet, P. Hanselaer, M. Dujardin, WR Ryckaert
This study explores the impact of wall luminance and correlated colour temperature (CCT) on the observers’ brightness perception and scene preference in a controlled, windowless office environment. A two-interval-forced-choice experiment was conducted with the 20 lighting scenes derived from five CCTs (2500–10 000 K) and four luminances (12–120 cd/m²). The results from 20 observers showed that a higher wall luminance significantly increased brightness. At equal luminances, different CCT values had no significant effect on brightness, consistent with some reports that CCT is not a reliable predictor of brightness when other photometric factors are held constant. Scene preference increased as wall luminance increased to approximately 72 cd/m², but a further increase in wall luminance to 120 cd/m² had no significant impact on preference. As the CCT increased from 2500 K, the preference increased up to approximately 4000 K, followed by a substantial decline from 5715 to 10 000 K.
{"title":"The effect of correlated colour temperature and wall luminance on spatial brightness and scene preference in a windowless office setup","authors":"L. Van de Perre, K. Smet, P. Hanselaer, M. Dujardin, WR Ryckaert","doi":"10.1177/14771535231154479","DOIUrl":"https://doi.org/10.1177/14771535231154479","url":null,"abstract":"This study explores the impact of wall luminance and correlated colour temperature (CCT) on the observers’ brightness perception and scene preference in a controlled, windowless office environment. A two-interval-forced-choice experiment was conducted with the 20 lighting scenes derived from five CCTs (2500–10 000 K) and four luminances (12–120 cd/m²). The results from 20 observers showed that a higher wall luminance significantly increased brightness. At equal luminances, different CCT values had no significant effect on brightness, consistent with some reports that CCT is not a reliable predictor of brightness when other photometric factors are held constant. Scene preference increased as wall luminance increased to approximately 72 cd/m², but a further increase in wall luminance to 120 cd/m² had no significant impact on preference. As the CCT increased from 2500 K, the preference increased up to approximately 4000 K, followed by a substantial decline from 5715 to 10 000 K.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124923434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-24DOI: 10.1177/14771535221145801
M. Leontopoulos, S. Leontopoulos, M. Knoop
Virtual reality (VR) introduces new approaches to creating virtual spaces for empirical studies and design processes. At the same time, VR platforms for research and education purposes in the field of daylight, such as one being built at TU Berlin, have to consider technical limitations. Besides the imperfections caused by simulation tools, VR head mounted displays (VR HMDs) bring additional shortcomings, one of the most obvious being the low maximum luminance compared to daylight. However, considering a typical viewing distance within VR HMDs is about 15 mm, and a usage duration can last up to 8 hours or more, concerns have arisen about the safety of displays with high luminance levels, particularly as a prototype claiming a maximum luminance of up to 6 000 cd/m2 has been introduced in the last years. Therefore, this paper compares the blue light hazard (BLH)-weighted radiances of VR HMDs to given exposure limits provided by the ICNIRP guidelines on limits of exposure to incoherent visible and infrared radiation and by the IEC 62471 (photobiological safety of lamps and lamp systems). The paper concludes with a statement on the BLH safety of VR HMDs.
{"title":"Consideration of blue light hazard for virtual reality head mounted displays","authors":"M. Leontopoulos, S. Leontopoulos, M. Knoop","doi":"10.1177/14771535221145801","DOIUrl":"https://doi.org/10.1177/14771535221145801","url":null,"abstract":"Virtual reality (VR) introduces new approaches to creating virtual spaces for empirical studies and design processes. At the same time, VR platforms for research and education purposes in the field of daylight, such as one being built at TU Berlin, have to consider technical limitations. Besides the imperfections caused by simulation tools, VR head mounted displays (VR HMDs) bring additional shortcomings, one of the most obvious being the low maximum luminance compared to daylight. However, considering a typical viewing distance within VR HMDs is about 15 mm, and a usage duration can last up to 8 hours or more, concerns have arisen about the safety of displays with high luminance levels, particularly as a prototype claiming a maximum luminance of up to 6 000 cd/m2 has been introduced in the last years. Therefore, this paper compares the blue light hazard (BLH)-weighted radiances of VR HMDs to given exposure limits provided by the ICNIRP guidelines on limits of exposure to incoherent visible and infrared radiation and by the IEC 62471 (photobiological safety of lamps and lamp systems). The paper concludes with a statement on the BLH safety of VR HMDs.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116870528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-20DOI: 10.1177/14771535221145606
M. Rea, A. Bierman, A. Thayer, C. Jarboe, M. Figueiro
The daily timings of our behavioural activities and physiological functions are regulated by the master biological clock in the brain. Disruption of these circadian rhythms can lead to poor performance and poor health. Consistent exposure to bright days and dim nights is necessary for circadian entrainment and, thus, for good sleep and good health. Since we spend most of our lives indoors, we often must rely on electric lighting for circadian entrainment. Surprisingly perhaps, current lighting practice does not purposely support circadian entrainment. A perceived barrier to promoting circadian entrainment with electric lighting is the absence of a standard test method for assessing the efficiency of luminaires for providing circadian-effective light to building occupants. Proposed is a measure for quantifying luminaire efficiency based on the electric power (watts) needed to reach the circadian stimulus criterion (CS = 0.3) at the eyes of a standard observer, termed Standard Observer Watts (SOWatt). The present paper describes how SOWatt can be applied to ceiling mounted, accent and table-top luminaires.
{"title":"Standard observer watts: Evaluating the efficiency of circadian-effective luminaires using a standard observer methodology","authors":"M. Rea, A. Bierman, A. Thayer, C. Jarboe, M. Figueiro","doi":"10.1177/14771535221145606","DOIUrl":"https://doi.org/10.1177/14771535221145606","url":null,"abstract":"The daily timings of our behavioural activities and physiological functions are regulated by the master biological clock in the brain. Disruption of these circadian rhythms can lead to poor performance and poor health. Consistent exposure to bright days and dim nights is necessary for circadian entrainment and, thus, for good sleep and good health. Since we spend most of our lives indoors, we often must rely on electric lighting for circadian entrainment. Surprisingly perhaps, current lighting practice does not purposely support circadian entrainment. A perceived barrier to promoting circadian entrainment with electric lighting is the absence of a standard test method for assessing the efficiency of luminaires for providing circadian-effective light to building occupants. Proposed is a measure for quantifying luminaire efficiency based on the electric power (watts) needed to reach the circadian stimulus criterion (CS = 0.3) at the eyes of a standard observer, termed Standard Observer Watts (SOWatt). The present paper describes how SOWatt can be applied to ceiling mounted, accent and table-top luminaires.","PeriodicalId":269493,"journal":{"name":"Lighting Research & Technology","volume":"11 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122352886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：