Pub Date : 2021-03-16DOI: 10.1080/15502724.2020.1860771
Michael P. Royer
ABSTRACT This tutorial article provides a comprehensive overview of the development and use of ANSI/IES TM-30-20, an American National Standard method for evaluating light source color rendition that is published by the Illuminating Engineering Society. Five years since its initial publication, TM-30 is increasingly used by lighting producers, specifiers, and researchers due to its superior accuracy and the expanded scope of provided information compared to predecessor tools for assessing color rendition. Making the most of these improvements requires people who use the method to be more knowledgeable and intentional, and this tutorial consolidates a range of information to assist with best practices. The article, arranged as a series of questions, includes information about the development of the standard, color rendering fundamentals, TM-30 measures and their meaning, TM-30 calculation details, and application of TM-30. The document does not provide instructions for performing TM-30 calculations, which is the purpose of the ANSI/IES TM-30-20 standard, which is freely available.
{"title":"Tutorial: Background and Guidance for Using the ANSI/IES TM-30 Method for Evaluating Light Source Color Rendition","authors":"Michael P. Royer","doi":"10.1080/15502724.2020.1860771","DOIUrl":"https://doi.org/10.1080/15502724.2020.1860771","url":null,"abstract":"ABSTRACT This tutorial article provides a comprehensive overview of the development and use of ANSI/IES TM-30-20, an American National Standard method for evaluating light source color rendition that is published by the Illuminating Engineering Society. Five years since its initial publication, TM-30 is increasingly used by lighting producers, specifiers, and researchers due to its superior accuracy and the expanded scope of provided information compared to predecessor tools for assessing color rendition. Making the most of these improvements requires people who use the method to be more knowledgeable and intentional, and this tutorial consolidates a range of information to assist with best practices. The article, arranged as a series of questions, includes information about the development of the standard, color rendering fundamentals, TM-30 measures and their meaning, TM-30 calculation details, and application of TM-30. The document does not provide instructions for performing TM-30 calculations, which is the purpose of the ANSI/IES TM-30-20 standard, which is freely available.","PeriodicalId":49911,"journal":{"name":"Leukos","volume":"90 1","pages":"191 - 231"},"PeriodicalIF":3.6,"publicationDate":"2021-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85931855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-01DOI: 10.1080/15502724.2020.1871361
T. Esposito
ABSTRACT Using comparative and iterative analyses of three-component spectral power distributions, this work demonstrates the advantage of locating radiation about the prime color wavelengths (near 450, 530, and 610 nm) over the anti-prime color wavelengths (near 490, 570, and 650 nm) for the purpose of maximizing color discrimination as measured by the Total Light Source Error Score, R d. To maximize color discrimination (minimize R d) most effectively in the design of a three-component spectrum, locate the primaries about the prime color wavelengths and increase their spectral width up to a full-width at half-maximum of 60 nm, at which R d is minimized. This work also details the internal logical consistency of quantifying color discrimination of a light source using R d, whereby the color discrimination ability of the daylight spectrum is set as ideal color discriminator meant to be replicated, not exceeded. Such internal logical consistency does not exist with quantifying color discrimination using gamut area, where is it demonstrably simple to exceed the performance of daylight (i.e., R g ≥ 100).
{"title":"Prime Color Wavelengths Improve Color Discrimination","authors":"T. Esposito","doi":"10.1080/15502724.2020.1871361","DOIUrl":"https://doi.org/10.1080/15502724.2020.1871361","url":null,"abstract":"ABSTRACT Using comparative and iterative analyses of three-component spectral power distributions, this work demonstrates the advantage of locating radiation about the prime color wavelengths (near 450, 530, and 610 nm) over the anti-prime color wavelengths (near 490, 570, and 650 nm) for the purpose of maximizing color discrimination as measured by the Total Light Source Error Score, R d. To maximize color discrimination (minimize R d) most effectively in the design of a three-component spectrum, locate the primaries about the prime color wavelengths and increase their spectral width up to a full-width at half-maximum of 60 nm, at which R d is minimized. This work also details the internal logical consistency of quantifying color discrimination of a light source using R d, whereby the color discrimination ability of the daylight spectrum is set as ideal color discriminator meant to be replicated, not exceeded. Such internal logical consistency does not exist with quantifying color discrimination using gamut area, where is it demonstrably simple to exceed the performance of daylight (i.e., R g ≥ 100).","PeriodicalId":49911,"journal":{"name":"Leukos","volume":"69 1","pages":"173 - 190"},"PeriodicalIF":3.6,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81621874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-25DOI: 10.1080/15502724.2020.1864396
Jiaye Li, P. Hanselaer, Kevin A. G. Smet
ABSTRACT In this study, the observer variability in a 10° achromatic color matching experiment using systematically different primaries under immersive, perceptually neutral (4673 K) and stable adapted viewing conditions have been investigated for four different sets of CIE color matching functions (CMFs). The matching reference was illuminated by a spectrally broadband light source at 70 cd/m2 and 4613 K. Fifty-four observers varying in age, gender, ethnicity and eye color participated. The results indicate that certain wavelength regions are more sensitive to generate interobserver variability, such as when a short wavelength primary (404 nm) was applied. Furthermore, of the primary sets investigated, that with peak-wavelengths (636–521–447 nm) close to the “typical” RGB-primaries widely known and used in industry had the smallest interobserver variability. In addition to the significant effect of primary set and CMF set, a significant effect of age on matching variability is also found, whereby the change of the blue primary resulted in a substantial difference in dispersion between younger and older observers, likely caused by age-induced yellowing of the lens. Furthermore, different primary sets tend to have a different impact on intra-observer variability than on interobserver variability. Finally, by comparing the observer variability in the current work with previous studies, the CIE standard deviate observer is found to substantially underestimate the interobserver variability, especially for the primary sets containing a 404 nm LED. Our observers also tend to have similar to smaller inter-variability than those reported in literature, possibly due to methodological differences.
{"title":"Impact of Color Matching Primaries on Observer Matching: Part II – Observer Variability","authors":"Jiaye Li, P. Hanselaer, Kevin A. G. Smet","doi":"10.1080/15502724.2020.1864396","DOIUrl":"https://doi.org/10.1080/15502724.2020.1864396","url":null,"abstract":"ABSTRACT In this study, the observer variability in a 10° achromatic color matching experiment using systematically different primaries under immersive, perceptually neutral (4673 K) and stable adapted viewing conditions have been investigated for four different sets of CIE color matching functions (CMFs). The matching reference was illuminated by a spectrally broadband light source at 70 cd/m2 and 4613 K. Fifty-four observers varying in age, gender, ethnicity and eye color participated. The results indicate that certain wavelength regions are more sensitive to generate interobserver variability, such as when a short wavelength primary (404 nm) was applied. Furthermore, of the primary sets investigated, that with peak-wavelengths (636–521–447 nm) close to the “typical” RGB-primaries widely known and used in industry had the smallest interobserver variability. In addition to the significant effect of primary set and CMF set, a significant effect of age on matching variability is also found, whereby the change of the blue primary resulted in a substantial difference in dispersion between younger and older observers, likely caused by age-induced yellowing of the lens. Furthermore, different primary sets tend to have a different impact on intra-observer variability than on interobserver variability. Finally, by comparing the observer variability in the current work with previous studies, the CIE standard deviate observer is found to substantially underestimate the interobserver variability, especially for the primary sets containing a 404 nm LED. Our observers also tend to have similar to smaller inter-variability than those reported in literature, possibly due to methodological differences.","PeriodicalId":49911,"journal":{"name":"Leukos","volume":"725 1","pages":"127 - 144"},"PeriodicalIF":3.6,"publicationDate":"2021-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/15502724.2020.1864396","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72400718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-18DOI: 10.1080/15502724.2020.1854779
C. Moscoso, K. Chamilothori, J. Wienold, M. Andersen, B. Matusiak
ABSTRACT The size of window openings is widely acknowledged as an important factor in our spatial perception. However, little is known about how the perception and preference of windows changes between countries, leaving a gap of knowledge regarding the applicability of research findings across latitudes. This article presents the outcomes of a study investigating regional differences in the perception of spaces with varying window size (small, medium, and large), space size (small and large), spatial context (working and social), and sky type (overcast and two types of clear sky). As the regional differences were the main studied factor, the study was performed in Norway, Switzerland, and Greece, representing northern, central, and southern European latitudes, respectively, and used virtual reality as a means to replicate the same experiment in different locations. In total, 406 participants evaluated eight spatial attributes using an 11-point Likert-type scale. Results indicated that regional differences could be observed in the participants’ responses, with significant differences in how pleasant and calm the space was perceived, found not only between participants in Greece and Norway in all the studied window sizes, but also between Greece and Switzerland for the medium and large windows, indicating that even small variations in latitude within Europe can affect the spatial perception. The findings of this study reveal that spaces with specific fenestration characteristics might not induce the same response across different latitudes in Europe, and thus, have important implications for daylighting and architectural design, which would motivate the use of region-specific parameters.
{"title":"Regional Differences in the Perception of Daylit Scenes across Europe Using Virtual Reality. Part I: Effects of Window Size","authors":"C. Moscoso, K. Chamilothori, J. Wienold, M. Andersen, B. Matusiak","doi":"10.1080/15502724.2020.1854779","DOIUrl":"https://doi.org/10.1080/15502724.2020.1854779","url":null,"abstract":"ABSTRACT The size of window openings is widely acknowledged as an important factor in our spatial perception. However, little is known about how the perception and preference of windows changes between countries, leaving a gap of knowledge regarding the applicability of research findings across latitudes. This article presents the outcomes of a study investigating regional differences in the perception of spaces with varying window size (small, medium, and large), space size (small and large), spatial context (working and social), and sky type (overcast and two types of clear sky). As the regional differences were the main studied factor, the study was performed in Norway, Switzerland, and Greece, representing northern, central, and southern European latitudes, respectively, and used virtual reality as a means to replicate the same experiment in different locations. In total, 406 participants evaluated eight spatial attributes using an 11-point Likert-type scale. Results indicated that regional differences could be observed in the participants’ responses, with significant differences in how pleasant and calm the space was perceived, found not only between participants in Greece and Norway in all the studied window sizes, but also between Greece and Switzerland for the medium and large windows, indicating that even small variations in latitude within Europe can affect the spatial perception. The findings of this study reveal that spaces with specific fenestration characteristics might not induce the same response across different latitudes in Europe, and thus, have important implications for daylighting and architectural design, which would motivate the use of region-specific parameters.","PeriodicalId":49911,"journal":{"name":"Leukos","volume":"191 1","pages":"294 - 315"},"PeriodicalIF":3.6,"publicationDate":"2021-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89754808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-17DOI: 10.1080/15502724.2020.1851606
I. Bournas
ABSTRACT This paper examines the association between daytime electric lighting use and perceived indoor daylight availability in residential spaces. In addition, occupant preferences were evaluated, in particular which rooms are prioritized in terms of daylight availability. The study deployed a questionnaire survey that was carried out in typical multi-dwelling apartment blocks in Malmö, Sweden (Latitude: 55.6 °N). Occupants were asked to report how often they use electric lighting during daylight hours (EL) in their kitchen, living room and main bedroom, and how much of the floor area they perceive as adequately daylit (DA) throughout the year. Responses EL and DA were measured in seven-point semantic differential scales, and were correlated (Spearman) to evaluate their association for different room groups. Groups were based on age, room function, façade orientation, balcony obstruction and fenestration geometry. In addition, occupants were asked which room they would choose if there had to be one underlit room. Results indicate that EL is strongly associated with DA in the overall room sample (rS = −0.588, p < .01, n = 225). The association is persistent across room groups of different characteristics, with the Spearman rank correlation coefficient ranging between −0.4 and −0.8, and not differing significantly between groups. In terms of preferences, a significantly high proportion of participants would choose the bedroom if there had to be one underlit room (62%, p < .05), while the kitchen was selected by only 5 out of 108 respondents.
摘要:本文研究了住宅空间中日间照明使用与室内日光可用性之间的关系。此外，还评估了居住者的偏好，特别是哪些房间在采光方面优先考虑。该研究在瑞典Malmö(纬度:55.6°N)的典型多住宅公寓楼中进行了问卷调查。居住者被要求报告他们在白天在厨房、客厅和主卧室使用电灯的频率，以及他们认为全年有多少地板面积是充足的日光(DA)。回答EL和DA采用7分语义差异量表进行测量，并采用Spearman相关法评估不同房间组的相关性。分组依据年龄、房间功能、立面朝向、阳台遮挡和开窗几何形状。此外，居住者还被问及，如果只有一个有灯光的房间，他们会选择哪个房间。结果表明，在整个房间样本中，EL与DA密切相关(rS =−0.588,p < 0.01, n = 225)。这种关联在不同特征的房间组中持续存在，Spearman等级相关系数在−0.4和−0.8之间，组间差异不显著。在偏好方面，如果必须有一个暗室，那么选择卧室的参与者比例非常高(62%，p < 0.05)，而在108名受访者中，只有5人选择了厨房。
{"title":"Association between Perceived Daylit Area and Self-reported Frequency of Electric Lighting Use in Multi-dwelling Buildings","authors":"I. Bournas","doi":"10.1080/15502724.2020.1851606","DOIUrl":"https://doi.org/10.1080/15502724.2020.1851606","url":null,"abstract":"ABSTRACT This paper examines the association between daytime electric lighting use and perceived indoor daylight availability in residential spaces. In addition, occupant preferences were evaluated, in particular which rooms are prioritized in terms of daylight availability. The study deployed a questionnaire survey that was carried out in typical multi-dwelling apartment blocks in Malmö, Sweden (Latitude: 55.6 °N). Occupants were asked to report how often they use electric lighting during daylight hours (EL) in their kitchen, living room and main bedroom, and how much of the floor area they perceive as adequately daylit (DA) throughout the year. Responses EL and DA were measured in seven-point semantic differential scales, and were correlated (Spearman) to evaluate their association for different room groups. Groups were based on age, room function, façade orientation, balcony obstruction and fenestration geometry. In addition, occupants were asked which room they would choose if there had to be one underlit room. Results indicate that EL is strongly associated with DA in the overall room sample (rS = −0.588, p < .01, n = 225). The association is persistent across room groups of different characteristics, with the Spearman rank correlation coefficient ranging between −0.4 and −0.8, and not differing significantly between groups. In terms of preferences, a significantly high proportion of participants would choose the bedroom if there had to be one underlit room (62%, p < .05), while the kitchen was selected by only 5 out of 108 respondents.","PeriodicalId":49911,"journal":{"name":"Leukos","volume":"292 1","pages":"83 - 102"},"PeriodicalIF":3.6,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79496818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-17DOI: 10.1080/15502724.2020.1864395
Jiaye Li, P. Hanselaer, Kevin A. G. Smet
ABSTRACT A good color description starts with the availability of accurate color-matching functions (CMFs) or cone fundamentals (CF). Recent work indicates a discrepancy between visual metamers and those calculated using the standard CIE CMFs or other CMF sets, especially for narrowband sources. In the current study, 54 observers (varying in age, gender, ethnicity, and eye color) performed a series of achromatic color-matching experiments with a 10° stimulus using eight different narrowband primaries under an immersive, perceptually neutral (4673 K) viewing conditions. The reference stimulus was provided by a 70 cd/m2 gray (4613 K) card illuminated by a spectrally broadband light source. The results confirm that substantial and significant differences between experimental and calculated metamers exist, particularly when a short wavelength primary (404 nm) is included and especially for the CIE 1931 2° CMFs. It is found that the primary set characterized by the peak wavelengths 636 nm, 521 nm, and 447 nm, which are close to those of typical RGB primaries widely used in industry, results in the most stable matching performance across all CMF sets. Finally, in addition to the impact of primary wavelength and CMF set, the potential effect of age, gender, ethnicity, and eye color has also been investigated. The effect of age on the color matches is found to be significant and is due to differences in spectral sensitivity of young and old observers with respect to the blue primary; the impact of observer gender, ethnicity, and eye color, on color-matching accuracy is not significant.
{"title":"Impact of Color-Matching Primaries on Observer Matching: Part I – Accuracy","authors":"Jiaye Li, P. Hanselaer, Kevin A. G. Smet","doi":"10.1080/15502724.2020.1864395","DOIUrl":"https://doi.org/10.1080/15502724.2020.1864395","url":null,"abstract":"ABSTRACT A good color description starts with the availability of accurate color-matching functions (CMFs) or cone fundamentals (CF). Recent work indicates a discrepancy between visual metamers and those calculated using the standard CIE CMFs or other CMF sets, especially for narrowband sources. In the current study, 54 observers (varying in age, gender, ethnicity, and eye color) performed a series of achromatic color-matching experiments with a 10° stimulus using eight different narrowband primaries under an immersive, perceptually neutral (4673 K) viewing conditions. The reference stimulus was provided by a 70 cd/m2 gray (4613 K) card illuminated by a spectrally broadband light source. The results confirm that substantial and significant differences between experimental and calculated metamers exist, particularly when a short wavelength primary (404 nm) is included and especially for the CIE 1931 2° CMFs. It is found that the primary set characterized by the peak wavelengths 636 nm, 521 nm, and 447 nm, which are close to those of typical RGB primaries widely used in industry, results in the most stable matching performance across all CMF sets. Finally, in addition to the impact of primary wavelength and CMF set, the potential effect of age, gender, ethnicity, and eye color has also been investigated. The effect of age on the color matches is found to be significant and is due to differences in spectral sensitivity of young and old observers with respect to the blue primary; the impact of observer gender, ethnicity, and eye color, on color-matching accuracy is not significant.","PeriodicalId":49911,"journal":{"name":"Leukos","volume":"97 1","pages":"104 - 126"},"PeriodicalIF":3.6,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86285234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-21DOI: 10.1080/15502724.2020.1854780
A. Batool, P. Rutherford, P. McGraw, T. Ledgeway, S. Altomonte
ABSTRACT The provision of daylight, fresh air, and of a view outdoors are among the known characteristics of windows. But how does the perception of a window differ when it becomes the primary way of connecting to the physical world outside? In the first half of 2020, many countries resorted to strict lockdown measures to control the spread of the SARS-CoV-2 virus. The impact of such confinement, and the restriction to movement and social contact between people, is currently undergoing intense research. As such, this study reports the findings of a global online survey, administered before and after the COVID-19 outbreak, aimed at identifying whether any significant difference related to the lockdown could be observed in the perception of windows. The results confirm a practically relevant increase in the importance given to windows as a way to provide an external view and a visual and social connection with other people. Conversely, the role of the window as a conveyor of information on weather and time of the day was less prevalent. This is one of the first studies evaluating the difference in the perception of windows within a period of enforced lockdown. The findings can help capture the psychological impacts of confinement on people and may be relevant when transferred to other domains where building occupants could strongly benefit from the restorative effects of window views.
{"title":"Window Views: Difference of Perception during the COVID-19 Lockdown","authors":"A. Batool, P. Rutherford, P. McGraw, T. Ledgeway, S. Altomonte","doi":"10.1080/15502724.2020.1854780","DOIUrl":"https://doi.org/10.1080/15502724.2020.1854780","url":null,"abstract":"ABSTRACT The provision of daylight, fresh air, and of a view outdoors are among the known characteristics of windows. But how does the perception of a window differ when it becomes the primary way of connecting to the physical world outside? In the first half of 2020, many countries resorted to strict lockdown measures to control the spread of the SARS-CoV-2 virus. The impact of such confinement, and the restriction to movement and social contact between people, is currently undergoing intense research. As such, this study reports the findings of a global online survey, administered before and after the COVID-19 outbreak, aimed at identifying whether any significant difference related to the lockdown could be observed in the perception of windows. The results confirm a practically relevant increase in the importance given to windows as a way to provide an external view and a visual and social connection with other people. Conversely, the role of the window as a conveyor of information on weather and time of the day was less prevalent. This is one of the first studies evaluating the difference in the perception of windows within a period of enforced lockdown. The findings can help capture the psychological impacts of confinement on people and may be relevant when transferred to other domains where building occupants could strongly benefit from the restorative effects of window views.","PeriodicalId":49911,"journal":{"name":"Leukos","volume":"06 1","pages":"380 - 390"},"PeriodicalIF":3.6,"publicationDate":"2021-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85979121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-02DOI: 10.1080/15502724.2020.1757461
E. Vicente, I. Arranz, D. Galarreta, P. Barrionuevo, M. Rodríguez-Rosa, S. Mar, JA Aparicio, B. Matesanz
ABSTRACT The purpose of this work is to analyze the interaction between the spectral transmittance of old-aged subjects, before and after cataract surgery and blue light-filtering intraocular lens implantation, and the spectral power distribution of common street lamps, under conditions typical of nighttime driving. We analyzed contrast threshold and visual reaction time in off-axis vision at different mesopic illumination conditions provided by high-pressure sodium and metal halide lamps. Three groups of subjects with different spectral transmittances participated: young subjects as control group, old-aged subjects with senile cataracts and the same subjects after cataract surgery and blue light-filtering IOL implantation. A clear interaction appears between the spectral power distribution and the spectral transmittance, depending on the visual task. Transparent ocular media allow benefiting from the greater short-wavelength content of the halide lamp. However, cataracts increase contrast threshold and visual reaction time values and also affects how the spectral power distribution influences these visual tasks. After surgery and intraocular lens implantation, visual performance improves for both lamps and the blue light-filter seems to influence spectral transmittance, which affects visual performance under light provided by greater short-wavelength content lamps. Cataract surgery is responsible for an improvement in contrast threshold and visual reaction time tasks, though blue light-filtering of the intraocular lens seems to prevent the visual system from benefiting from lamps with greater emission at short wavelengths.
{"title":"Effect of Different Spectral Power Distributions on Mesopic Visual Performance with Blue Light-filtering Intraocular Lens","authors":"E. Vicente, I. Arranz, D. Galarreta, P. Barrionuevo, M. Rodríguez-Rosa, S. Mar, JA Aparicio, B. Matesanz","doi":"10.1080/15502724.2020.1757461","DOIUrl":"https://doi.org/10.1080/15502724.2020.1757461","url":null,"abstract":"ABSTRACT The purpose of this work is to analyze the interaction between the spectral transmittance of old-aged subjects, before and after cataract surgery and blue light-filtering intraocular lens implantation, and the spectral power distribution of common street lamps, under conditions typical of nighttime driving. We analyzed contrast threshold and visual reaction time in off-axis vision at different mesopic illumination conditions provided by high-pressure sodium and metal halide lamps. Three groups of subjects with different spectral transmittances participated: young subjects as control group, old-aged subjects with senile cataracts and the same subjects after cataract surgery and blue light-filtering IOL implantation. A clear interaction appears between the spectral power distribution and the spectral transmittance, depending on the visual task. Transparent ocular media allow benefiting from the greater short-wavelength content of the halide lamp. However, cataracts increase contrast threshold and visual reaction time values and also affects how the spectral power distribution influences these visual tasks. After surgery and intraocular lens implantation, visual performance improves for both lamps and the blue light-filter seems to influence spectral transmittance, which affects visual performance under light provided by greater short-wavelength content lamps. Cataract surgery is responsible for an improvement in contrast threshold and visual reaction time tasks, though blue light-filtering of the intraocular lens seems to prevent the visual system from benefiting from lamps with greater emission at short wavelengths.","PeriodicalId":49911,"journal":{"name":"Leukos","volume":"2 1","pages":"59 - 74"},"PeriodicalIF":3.6,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82965444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-02DOI: 10.1080/15502724.2020.1834283
K. Houser
Estimates, precision, and accuracy all involve the concept of error, but in different ways. An estimate is an approximate prediction of the amount of something. Precision refers to the reproducibil...
估计、精度和准确性都涉及误差的概念，但方式不同。估计是对某物数量的近似预测。精密度指的是再现性。
{"title":"Estimates, Precision, Accuracy, and Adaptation in Applied Lighting","authors":"K. Houser","doi":"10.1080/15502724.2020.1834283","DOIUrl":"https://doi.org/10.1080/15502724.2020.1834283","url":null,"abstract":"Estimates, precision, and accuracy all involve the concept of error, but in different ways. An estimate is an approximate prediction of the amount of something. Precision refers to the reproducibil...","PeriodicalId":49911,"journal":{"name":"Leukos","volume":"48 1","pages":"1 - 2"},"PeriodicalIF":3.6,"publicationDate":"2021-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90294242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-02DOI: 10.1080/15502724.2018.1533853
Purnima Mandal, D. Dey, B. Roy
ABSTRACT The design of an indoor lighting system for a sustainable building should comply with the recommended maximum limit of lighting power density. The occupants’ visual comfort and visual performance are to be ensured by complying with some mutually conflicting lighting design parameters, such as maintained average illuminance, overall uniformity, and maximum unified glare rating, to the recommended limits. Judicious balance among these multiple conflicting design parameters is a practical design problem. This article aims to address these aspects of indoor lighting design by applying a particle swarm optimization (PSO) algorithm in a developed lighting computation program. The objective function is formulated with maximum or minimum limits for the design parameters recommended by international standards. The effectiveness of the developed program is evaluated by designing an indoor lighting system with commercially available luminaires for an office space that ensures optimized visual comfort, energy efficiency, and initial cost. Optimized results are validated by DiaLux simulation and a maximum deviation of 2.27% is found. Thus, the results show good agreement with DiaLux simulation and significant improvement in the uniformity of illuminance (0.90) compared to the recommended minimum value (0.70) and in discomfort glare (16) compared to the recommended allowable maximum value (19). The developed program establishes the usefulness of the PSO algorithm to optimize the luminaire layout for an indoor general lighting scheme.
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