A variety of LED types can be employed for street and road lighting purposes. White phosphor-converted LEDs represent the most widely used option. However, amber LEDs are increasingly being used to reduce some negative effects associated with light pollution. These LEDs can be manufactured using both phosphor-converted and monochromatic direct chip technologies. This paper addresses the link between the reduction in short-wavelength light emissions which contribute to sky glow and the energy efficiency of LED-based road lighting. This paper focuses on an example illustrating the common misconception that reducing light pollution also means saving energy. Through the consideration of how spectral power distribution influences both mesopic vision and the amount of emitted blue light, it has been concluded that while monochromatic direct amber LEDs consume more energy than their white or amber phosphor-converted counterparts, their use in outdoor lighting is justifiable due to their potential effects of reducing sky brightness.

The color matching possibilities between (reference) phosphor-converted LEDs (pc-LEDs) and replacement metameric LEDs made by color mixing technology (cm-LEDs) were evaluated in the classical 20th century CIE 1976 color space developed for perpendicular viewing (based on a 2° colorimetric observer) and in the latest CIE 2015 cone fundamental color space developed for wide field of view observers (10° colorimetric observer). For each given pc-LED 10 different sets of cm-LEDs were designed and evaluated for color consistency in 2°and 10° color spaces. There were 10 different B-color LEDs considered along with constant RGA LEDs. There are thousands of possible distributions that are metameric in the CIE 1976 color space and thousands of possible distributions that are metameric in the CIE 2015 color space for each set of LEDs. From the population of SPDs, we selected 10 metameric SPDs characterized by maximum differences between chromaticities. The results provide evidence that evaluating LED color consistency based only on the CIE 1976 color space is not fully informative because it may provide inaccurate information about light color consistency when the observer has a wide field of view. There are cases showed in this paper where cm-LEDs are color consistent in the CIE 2015 color space but are not color consistent in the CIE 1976 color space and vice versa. Including color consistency in the new CIE 2015 color space should be treated as an additional evaluation tool proving the user additional information relevant to the intended use of the LED. The results illustrate differences in LED color consistency evaluated in different color spaces and provides incentive go beyond the 20th century color space in the evaluation of cm-LED color consistency.

This study carried out a literature search and selection in accordance with the PRISMA 2020 protocol to conduct a complete review of the literature describing the electrical, photometrical, and colorimetric parameters of LEDs. Based on it, a significant research gap was found in the field of LED-based lighting retrofits. We prove that there is a lack of publications indicating the relationship between the energy consumption of LED retrofits and user preferences concerning the quality of lighting. This article presents an effective new method for selecting LEDs to retrofit typical 3000, 4000, and 6500 K fluorescent lighting installations in buildings. It is shown that when selecting an LED replacement for a fluorescent source, consideration of the classically used parameters in the field of lighting technology to describe the quality of white light, specifically correlated color temperature and the color rendering index, is insufficient. We demonstrate that energy efficiency and the color preference criteria for retrofitted LEDs must be considered and balanced with the potential impact on circadian rhythms as assessed by the melanopic daylight efficacy ratio. This research proves that LED replacements with the best color preference properties (P1 class in the CPC classification of ANSI/IES TM30-20 method) correspond to the least energy-efficient light sources.

Fluorescent lamps (FLs) used for general lighting due to European Union legislation will be withdrawn from sale by 2023. The LEDs which are proposed as substitute of FL should provide the same quality of lighting and visual comfort. The research on substituting FL lamps is based on the multi-criteria parameterization. It is indicates that LEDs substituting the FLs may not meet the end user expectations due to the Color Preference Criteria. The paper compare typical FL (4100 K) lamp named by CIE as illuminant FL3.5 with its corresponding LED substitutes available on the market. The LED substitute selection criterion were value of Corelated Color Temperature (CCT) and chromaticity point which was must be within ellipse provided by ANSI C78.376 document for 4100 K CCT. Full Text: PDF ReferencesW. Żagan, Conditions necessary to replacing the conventional lamps by energy-saving lamps, Przeglad Elektrotechniczny, R. 85, 100 (2009). DirectLink M. Zalesinska, J. Zablocka, K. Wandachowicz, "Measurement and evaluation of selected parameters for non-directional household lamps", Prz. Elektrotech. 94, 188 (2018). CrossRef D. Czyżewski, "LED substitutes of conventional incandescent lamps", Prz. Elektrotech. 88, 123 (2012). DirectLink D. Czyżewski, "LED substitutes of conventional incandescent lamps(2)", Prz. Elektrotech. 91, 199 (2015). CrossRef Document of the International Commission on Illumination CIE 015:2018 "Colorimetry, 4th Edition". CrossRef CIE 13.3-1995: Method of measuring and specifying colour rendering properties of light sources," Commission Internationale de l'Eclairage, Vienna, Austria (1995). DirectLink Y. Ohno, M. Fein, C. Miller, "Vision Experiment on Chroma Saturation 2016 DOE SSL R&D Workshop 14 for Color Quality Preference", CIE 216 :2015, 60 (2015). DirectLink Y. Ohno, "Practical Use and Calculation of CCT and Duv", LEUKOS- J. Illum. Eng. Soc. N. Am. 10, 47, (2014). CrossRef Y. Wang, M. Wei, "Preference among light sources with different Duv but similar colour rendition: a pilot study", Ligh. Res. Technol. 50, 1013 (2018). CrossRef M. Royer, Analysis of color rendition specification criteria, Light-Emitting Devices, Materials, and Applications. 10940. International Society for Optics and Photonics, (2019). CrossRef ANSI/IES TM-30-20, IES Method for Evaluating Light Source Color Rendition. DirectLink J. Kowalska, "Analysis of parameters describing the quality of the color rendering of light sources according to the IES TM-30-15 and the CIE 013.3-1995", Prz. Elektrotech. 93, 50 (2017). CrossRef J. Kowalska, I.Fryc, "Colour rendition quality of typical fluorescent lamps determined by CIE Colour Fidelity Index and Colour Rendering Index", Prz. Elektrotech. 95, 94 (2019). CrossRef D. Aurelien, et al., "Development of the IES method for evaluating the color rendition of light sources", Opt. Express, 23, 15888 (2015). CrossRef W. Żagan, "Honestly and prudently about LED - Future and present state of LED application in lighting", Prz. Elektrotech. 84, 1 (2008). DirectLink W. Żagan, "Theoretical considerations on luminous efficacy and colour rendering of light sources", Prz. Elektrotech. 89, 284, (2013). DirectLink M. Listowski, "The real and modeled values of photometric and colorimetric parameters comparison of white LEDs operating at wide temperature range", Prz. Elektrotech. 98, 57 (2022). CrossRef R. Supronowicz, J. Fan, M. Listowski, A. Watras, I. Fryc, "Application of different metrics for describing light color quality of white LED". Photonics Lett. Pol. 13, 31 (2021). CrossRef I.Fryc, "Measurement techniques of optical LEDs properties performed with compliance conformity with CIE 127:2007 standard", Prz. Elektrotech. 85, 317 (2009). DirectLink I. Fryc, T. Dimitrova-Grekow, "An Automated System for Evaluation of the Quality of Light Sources" Proceedings of 2016 IEEE Lighting Conference of the Visegrad Countries (Lumen V4), CrossRef P. Jakubowski, J. Kowalska, R. Supronowicz, I. Fryc, "The Influence of Spectral Measurements Uncertainty of Fluorescent Lamps on Calculated Value of Their Relative Melanopic Weighted Irradiance and Colour Quality Parameters", 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4), 1 (2018). CrossRef P. Zhu, H. Zhu, G. C. Adhikari, S. Thapa, "Design of circadian white light-emitting diodes with tunable color temperature and nearly perfect color rendition", OSA Contin. 2, 2413 (2019). CrossRef Q. Dai, Y. Huang, L. Hao, Y. Lin, K. Chen, "Spatial and spectral illumination design for energy-efficient circadian lighting", Build. Environ. 146, 216 (2018). CrossRef A. Sánchez-Cano, J. Aporta, "Optimization of Lighting Projects Including Photopic and Circadian Criteria: A Simplified Action Protocol". Appl. Sci. 10, 8068 (2020). CrossRef CIE International Standard DIS 026/E:2018 CIE System for Metrology of Optical Radiation for ipRGC-Influenced Responses to Light, CrossRef I. Fryc, P. Jakubowski, K. Kołacz, "Analysis of optical radiation parameters of compact discharge HID lamps and LED COB modules used for illuminating shop windows, Prz. Elektrotech. 93, 186 (2017). CrossRef I. Fryc, "LED's spectral power distribution under different condition of operating temperature and driving current", Prz. Elektrotech. 86, 187 (2010). DirectLink D. Mozyrska, M. Wyrwas, I.Fryc, "The determination of the LEDs colorimetric parameters, in the range of their operating temperature", Prz. Elektrotech. 88, 232 (2012). DirectLink M. Kreissl, T. Q. Tien, J. W. Tomm, "Spatially resolved and temperature dependent thermal tuning rates of high-power diode laser arrays", Appl. Phys. Lett. 88, 133510 (2006). CrossRef K. Wandachowicz, K. Domke, "Measurements of the temperature-dependent changes of the photometrical and electrical parameters of LEDs", Prz. Elektrotech. 84, 114 (2008). DirectLink I. Fryc, "The spectral power distribution of LED driven by square shape pulses", Prz. Elektrotech. 88, 131 (2012). DirectLink J. Fan, Y. Li, I....

Selecting LED retrofits for examination rooms in healthcare buildings involves setting the right balance between lighting quality and energy efficiency. In the case of LEDs incorporated in luminaires used in medical examination rooms, it is essential to consider not only the correlated color temperature (CCT) and color rendering index (CRI Ra) in compliance with the lighting standards, but also the cyanosis observation index (COI) that meets the more demanding regulations of certain countries. In this work, the Color Preference Criteria (CPC) method is used to select LED retrofits for this application. The LEDs classified as P1 according to the CPC method were found to meet the required COI level.

Typically the sensitivity V2 (λ) for a 2° standard observer is used at photometric measurments. Nevertheless, the light reach the human eye from wider field of view. This fact motivated the International Commission on Illumination to introduce the 10° supplementary observer with sensitivity V10 (λ). This paper analyzes the impact of transition from V2 (λ) to V10 (λ) on measured pc-LEDs illuminance values. The results indicate that the maximum difference is 2% for 3000 K pc-LEDs, 4% for 4000 K pc-LEDs, and 6% for 6500 K pc LEDs. Full Text: PDF References K.S. Gibson, E.P.T. Tyndall, "Visibility of Radiant Energy", Scientific Papers of the Bureau of Standards, 19, 131 (1923). CrossRef E.P. Hyde, W.E. Forsythe, F.E. Cady, J. Frank. "The visibility of radiation", Inst. 185, 829 (1918). CrossRef I. Fryc, M. Listowski, R. Supronowicz, "Going beyond the 20th century color space to evaluate LED color consistency", Opt. Express 31(23), 38666 (2023). CrossRef R. Supronowicz, J. Fan, M. Listowski, A. Watras, I. Fryc, "Application of different metrics for describing light color quality of white LED", Photonics Lett. Pol 13, 32 (2021). CrossRef W.S. Stiles, J.M. Burch, "N.P.L. Colour-matching Investigation: Final Report (1958)", Optica Acta: Int. J. Opt. 6, 1 (1959). CrossRef CIE 165:2005 CIE 10 Degree Photopic Photometric Observer, (2005). DirectLink J. Nathans, D. Thomas, D.S. Hogness, "Molecular Genetics of Human Color Vision: The Genes Encoding Blue, Green, and Red Pigments", Science 232, 193 (1986). CrossRef A. Roorda, A.B. Metha, P. Lennie, D.R. Williams, "Packing arrangement of the three cone classes in primate retina", Vis. Res. 41, 1291 (2001). CrossRef H. Hofer, J. Carroll, J. Neitz, M. Neitz, D.R. Williams, "Organization of the Human Trichromatic Cone Mosaic", J. Neurosci. 25, 9669 (2005). CrossRef C.A. Curcio, K.R. Sloan, R.E. Kalina, A.E. Hendrickson, "Human photoreceptor topography", J. Comp. Neurol. 292, 497 (1990). CrossRef D. Mustafi, A.H. Engel, K. Palczewski, "Structure of cone photoreceptors", Prog. Retin. Eye Res. 28, 289 (2009). CrossRef E.M. Wells-Gray, S.S. Choi, A. Bries, N. Doble, "Variation in rod and cone density from the fovea to the mid-periphery in healthy human retinas using adaptive optics scanning laser ophthalmoscopy", Eye 30, 1135 (2016). CrossRef S. Bara, M.A. Bonmati-Carrion, J.A. Madrid, M.A. Rol, "Multispectral estimation of retinal photoreceptoral inputs", Photonics. Lett. Pol 11, 60 (2019). CrossRef CIE 170-2:2015 Fundamental Chromaticity Diagram With Physiological Axes - Part 2: Spectral Luminous Efficiency Functions And Chromaticity Diagrams, (2015). DirectLink I. Fryc, T. Dimitrova-Grekow, "An automated system for evaluation of the quality of light sources", 2016 IEEE Lighting Conference of the Visegrad Countries (Lumen V4) (2016). CrossRef I. Fryc, "Spectral correction of a detector used in illuminance measurements", Proc. SPIE 3820, 343 (1999). CrossRef H. Wright, C.L. Sanders, D. Gignac, "Design of Glass Filter Combinations for Photometers", Appl. Opt. 8, 2449 (1969). CrossRef S. Winter, D. Lindner, A. Sperling, G. Sauter, S. Brown, T. Larason, Y. Zong, Y. Ohno, Proceedings of the 9th International Conference on New Developments and Applications in Optical Radiometry (NEWRAD), Davos, 2005. DirectLink I. Fryc, P. Tabaka, "The influence of different photometric observers on luxmeter accuracy for LEDs and FLs lamps measurements", Opt. Appl. XLIX, 345 (2019). CrossRef U.S. Energy Information Administration, Commercial Buildings Energy Consumption Survey (2021). DirectLink United Nations Environment Programme (2013). Minamata convention on mercury: text and annexes, (2013). DirectLink M. Listowski, R. Supronowicz, "Color quality consideration when switching from FL to LED", Photonics Lett.Pol. 14, 56 (2022). CrossRef J. Cho, J.H. Park, J.K. Kim, E.F. Schubert, "White light-emitting diodes: History, progress, and future", Phot. Rev. 11, 1600147 (2017). CrossRef K. Bando, K. Sakano, Y. Noguchi, Y. Shimizu, "Development of High-bright and Pure-white LED Lamps", J. Light & Vis. Env. 22, 2 (1998). CrossRef M. Listowski, "Porównanie modelowanych oraz rzeczywistych wartości parametrów świetlnych i kolorymetrycznych białych diod LED pracujących w szerokim zakresie temperatur", Przegląd Elektrotechniczny 1, 59 (2022). CrossRef W. Song, D. Durmus, "Evaluating Energy Efficiency and Colorimetric Quality of Electric Light Sources Using Alternative Spectral Sensitivity Functions", Buildings 12, 2220 (2022). CrossRef S. Jost, A. Thorseth, T. Poikonen, P. Blattner, T. Gerloff, A. Kokka, P. Dekker, M. Smid, A. Ferrero, T. Kubarsepp, P. Gal, S. Källberg, A. Klej, G. Brida, T. Reiners, K. Ludwig, M. Schneider, L. Hui, EMPIR 15SIB07 PhotoLED - Database of LED product spectra, (2021) CrossRef M. Royer, Real Light Source SPDs and Color Data for Use in Research, (2023). CrossRef ANSI C78.377 Electric Lamps - Specifications For The Chromaticity Of Solid-State Lighting Products, (2017). CrossRef Y. Ohno, "Practical Use and Calculation of CCT and Duv", LEUKOS 10(1), 47 (2014). CrossRef