Abstract: Light pollution due to exterior lighting is a rising concern. While glare, light trespass and general light pollution have been well described, there are few reported studies on the impact of light pollution on insects. By studying insect behavior in relation to artificial lighting, we suggest that control of the UV component of artificial lighting can significantly reduce its attractiveness, offering a strong ability to control the impact on insects. Traditionally, the attractiveness of a lamp to insects is calculated using the luminous efficiency spectrum of insect rhodopsin. This has enabled the development of lamps that emit radiation with wavelengths that are less visible to insects (that is, yellow lamps). We tested the assumption that the degree of visibility of a lamp to insects can predict its attractiveness by means of experimental collections. We found that the expected lamp's visibility is indeed related to the extent to which it attracts insects. However, the number of insects attract...

Abstract: A Meta-Analysis of Energy Savings from Lighting Controls in Commercial Buildings Alison Williams, Barbara Atkinson, Karina Garbesi, and Francis Rubinstein Energy Analysis Department Lawrence Berkeley National Laboratory Berkeley, CA 94720 Erik Page Erik Page & Associates, Inc. September 2011 This work was supported by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy, Building Technologies Program under Contract No. DE-AC02-05CH11231.

Abstract: This article discusses spatial brightness and visual clarity to question whether these are similar or different phenomena of visual perception. A review of the descriptions reported in past articles suggests that some researchers consider spatial brightness and visual clarity to be different, although this is not a universal opinion. In contrast, analyses of the results of brightness and clarity judgments given by naive test participants to lighting of different spectral power distribution in previous work suggests that similar judgments are given for brightness and clarity when the meanings of these items are undefined in the test procedure and this is the more frequent situation. This review demonstrates the need for care in defining and interpreting category rating scales.

Abstract: High dynamic range (HDR) imaging techniques are increasingly used by lighting researchers in building applications to capture luminances in the field of view. This paper deals with the photometric calibration and more particularly with vignetting effect correction, which is one of the steps necessary to ensure reliable data. The vignetting effects of four similar devices (two identical fisheye lenses successively mounted on two identical cameras) were first determined for several apertures. The symmetry, noninfluence of the color of the target, and the similarity of vignetting between the devices were evaluated with root mean square error. Finally, the mapping function of the fisheye lens was checked. This study shows that the vignetting filters determined for one device (a SIGMA 4.5 mm F2.8 fisheye lens mounted on a CANON 40D camera) can be reasonably used by other researchers using similar photographic materials (that is, the same brands and models).

Abstract: (2012). Status of Solid-State Lighting Based on Entries to the 2010 US DOE Next Generation Luminaire Competition. LEUKOS: Vol. 8, No. 4, pp. 237-259.

Abstract: An experiment was conducted to examine the effect of tuning optical radiation on brightness perception for younger (18–25 years of age) and older (50 years of age or older) observers. Participants made forced-choice evaluations of the brightness of a full factorial of stimulus pairs selected from two groups of four metameric stimuli The large-field stimuli were created by systematically varying either the red or the blue primary of an RGB LED mixture. The results indicate that light stimuli of equal illuminance and chromaticity do not appear equally bright to either younger or older subjects. The rank-order of brightness is not predicted by current models of human vision or theories of brightness perception including scotopic to photopic or cirtopic to photopic ratio theory, prime color theory, correlated color temperature, V(λ)-based photometry, color quality metrics, linear brightness models, or color appearance models. Age may affect brightness perception when short-wavelength primaries are use...

Abstract: LED lighting is often presented as the lighting technology of the future. Yet there are differences in the luminous intensity distributions between luminaires that employ conventional light sources and those that employ LEDs. The optical engineer faces a new challenge of designing for a spatially extended and nonuniform light source. Consequently, a new approach is needed for the optical design of planar LED luminaires. Luminaire optical design is typically performed using a combination of ray-tracing and trial-and-error experimentation with the goal of obtaining a target luminous intensity distribution. The number of iterations can be reduced by utilizing optimization algorithms. This study aimed to develop a numerical model for luminous intensity distribution of planar prism LED luminaires and apply the optimization algorithm for prism angle design. A calculation process for the prism optical design of a planar prism LED luminaire was developed. To assess the accuracy of the numerical model, a c...

Abstract: The effect of spectrum on the visibility of roadway lighting targets was investigated. The experiment focused on the relation between average visibility ratings and small target visibility (STV) under installations that employed LED and HPS light sources. Achromatic targets were more visible under LEDs illumination conditions than under HPS illumination conditions. The results also suggest that the visibility of colored objects on the road was better under LEDs illumination conditions in comparison to HPS. The results cannot be generalized to all LED light sources, but are likely indicative of LEDs with similar spectral power distributions (SPDs). Relative visibility under source types with different SPDs, and which provide different luminance distributions, should merit consideration when selecting a light source for roadway lighting.

Abstract: This paper addresses the lighting design strategies and advanced technologies used in the design of the Masdar Headquarters, an office building set within Abu Dhabi, the United Arab Emirates. The building, which is now under construction, is expected to have 103% net-positive energy use. The work emphasizes design goals centered on human visual needs and investigates lighting conditions related to sustainable and climatically responsive architecture. The optimization of the daylighting design strategies is presented, including a shading trellis with integrated photovoltaic cells, the conical courtyards, and the sawtooth facade. The study highlights electric lighting concepts predicated on available daylight and advanced lighting controls that incorporate digital dimming ballasts, programmed and user operable controls, daylight harvesting, and occupancy monitoring. Simulation was utilized to investigate parameters such as daylight factor, daily radiant energy including photosynthetically active rad...

Abstract: This paper aims to design a prototype tangible user interface (TUI) for lighting control, and test its usability and end-user experience against a prototype conventional interface. Usability is concerned with easier understanding of control functions. End-user experience is concerned with explicating the quality of end-users' experience such as fun and pleasure of use. TUIs that offer end-users freedom of personal expression alongside functional information are proposed as a basis for making lighting control systems easier to understand and more pleasurable to use. Three dominant views on tangible interaction are explored to derive a set of synthesized principles for designing tangible lighting control interfaces. These principles—which determine what end-users should see and do while using lighting control interfaces and provide specific guidelines for enhancing their physical interaction possibilities—are used to design a prototype tangible interface. Several tests were performed to obtain end-u...

Abstract: Glare is a common visual stressor of office work and in today's offices the prevalence of information and communication technologies adds additional mental demands. The aim of this study was to explore the role of light as a cognitive stressor in visual display terminal (VDT) work. We used a large area light source in a 2 × 2 × 2 full factorial experimental design. We assessed cognitive efficiency using the RTLX method and cognitive effectiveness using the RST method in different lighting scenarios. The main effects analysis showed lower working memory capacity for high luminance and large source, with statistically significant lower cognitive performance in prosaccade conditions. No statistically significant relationship was found between cognitive efficiency and the experimental factors.

Abstract: There has been growing interest in vehicle interior lighting for both functional and aesthetic purposes. Although there is a large body of research on nighttime driver vision and vehicle exterior lighting, there has been little research attention to vehicle interior lighting. This report includes a brief review of some of the research that has been done, and presents the results of a nighttime field study that was performed to contribute to the understanding of how vehicle interior lighting affects some basic aspects of driver vision. Participants in the study were asked to perform two tasks while seated in a stationary experimental car on a closed test road at night: 1) detecting pedestrians on the road ahead, and 2) rating the subjective brightness of a reflected veiling light on the windshield. The veiling light was varied in both luminance and color. The results indicated that pedestrian detection was closely related to photopic photometric measures, suggesting that the pedestrian task was inf...

Abstract: Design rules for small power T2 and T3 compact fluorescent lamps (CFLs) with power ranging from 5 to 23 W were investigated to develop high efficiency lamps. The relationships between light performance, electrical characteristics and tube design were studied. Phenomenological formulas of light efficacy were deduced from the experimental data. Calculations based on the design formulas are compared with the measured data for several brands and powers of lamps to verify the validity of the design formulas. The calculations fit well with the measured data. Maps relating light efficacy, lamp power and lamp geometry were created from the phenomenological formulas. The maximum light efficacy curves produced provide guidance for the development of high efficacy CFL lamps.

Abstract: 00,000 hours is equivalent to 11 years, 149 days, and 16 hours. For an LED sold today with a lifetime claim of 100,000 hours, an infallible test of lifetime and lumen maintenance would have had to have started sometime in 2001. For the high-tech world of solid state electronics, that was a long, long time ago. 2001 was two years before the first BlackBerry smartphone was released. The first Apple iPhone wasn’t released until 2007. No one is at fault for not performing infallible lumen maintenance tests. They didn’t start in 2001 because the LEDs sold today did not yet exist.

Abstract: Two simulation methods were developed to model the lighting energy use for a real office building and the results of those simulations were compared to submetered lighting energy data from that building. Three deterministic schedules and six stochastic first-order Markov-models were used to assess annual lighting energy density and peak demand density at both the office-level and the building-level. The stochastic simulations, which apply only to the private offices, resulted in much lower annual energy density and peak demand density predictions due to interactions of users with the lighting and shade controls, and widely different daily use profiles. For the whole-building simulations, comparing all three deterministic schedules resulted in an inverse relationship between peak demand density and annual energy density; the closest correlation with the submetered data was found through the most building-specific but least empirically-vetted schedule-based simulation.

Abstract: But distracting reflections are not the only consideration. Discomfort glare is a visual annoyance caused by luminance in the field-of-view that is considerably greater than the luminance to which the visual system is adapted [IES 2011]. Discomfort glare does not necessarily affect short-term performance or a person’s ability to perform a visual task. As a result, a little glare may seem too harmless to merit serious concern or corrective action. But it’s a mistake to overlook discomfort glare because it is insidious. Any constant annoyance—whether from temperature, noise, chronic pain, veiling reflections, or excessively bright luminaires—should be expected to affect long-term performance and productivity.

Abstract: The IES BUG rating system is useful for classifying outdoor luminaires when considering light trespass, sky-glow, and glare in accordance with the joint IDA-IES Model Lighting Ordinance (MLO). There are, however, limits to what can be measured in the laboratory. IES TM-15-11 requires that a luminaire with an uplight rating of U0 emits zero lumens into the upper hemisphere, while a U1 uplight rating or a G0 glare rating for high viewing angles requires fewer than 10 lumens. Given that the luminaire is emitting thousands of lumens and that the laboratory room surfaces have a diffuse reflectance of at least two percent, it is physically impossible to measure zero lumens, and extremely difficult to measure fewer than 10 lumens.Consequently, a U0 glare rating can only be obtained by physical examination of the luminaire and post-processing of the measured photometric data. Similarly, a U1 uplight rating or a G0 glare rating for high viewing angles is likely the result of data manipulation. The MLO User...

Abstract: Rather than being complementary, street lighting and facade lighting are typically designed independently of each other. As a result, light from street lighting luminaires might spill onto building facades and influence characteristics of the facade lighting including required light levels and color. Conversely, facade lighting might reflect onto the street and contribute to the street illumination. This manuscript presents an integrated approach to analyzing the interaction between the street and facade lighting in consideration of light pollution control. A generic street model with various calculation grids was studied. It was found that a moderately lit facade contributes to a horizontal illuminance of 5 lux or more on the street and a vertical illuminance of 4 lux or more 1.5 m above the sidewalk. An over-illuminated street may result when both street and facade lighting exist without reference to each other. The size of the light-pollution calculation grid and the use of a 3-D illuminance gr...