Perceptual and emotional effects of light and color in a simulated retail space

This article aims to address two aspects of lighting often treated intuitively by designers in charge of creating retail atmospheres, that is, the impact of color and light distribution, as design variables. The study comprised a controlled experiment with a repeated measure design with three directions of lighting (front, overhead, and wallwasher), as the within‐subject factor and four color combinations of the walls (yellow‐blue, magenta, gray, and green‐magenta), as the between‐group variable. The perceptual (visually) and emotional responses of 184 participants revealed the interplay between light and color on these psychological outcomes. Specifically, the results showed that the overhead direction of lighting improves the appearance of the less favored color conditions, either in terms of lack of visual complexity (monochromatic) or color itself (gray). In turn, the wallwasher lighting emphasized these attributes, differing according to visual or emotional aspects. In retailing, emotional dimensions such as activation and evaluation are desired, and they were confirmed across all the lighting and color conditions of this study. The results provide designers with certain perceptual cues regarding colors and their lighting mode to create desirable impressions and affect in retail spaces.     

发光材料在防眩光交通监控补光照明中的应用

交通监控补光源在工作时产生的强烈眩光会干扰驾驶员视线,从而给道路安全带来了隐患。考虑到人眼对于不同色光的敏感程度,通过改进补光源的光谱分布,提高人眼较不敏感的红光部分,能够有效地减轻眩光。这需要改变发光器件中的荧光粉组成。本文通过高温固相反应法制备了铈掺杂的钇铝镓石榴石基黄绿色荧光粉以及铕掺杂的钙锶铝硅氮化物红色荧光粉。所合成样品均为纯相,粉末颗粒分布均匀。光谱测试表明,样品能够被可见蓝光有效激发,发射光分别位于黄绿光区和红光区。将上述荧光粉与蓝光芯片复合封装得到发光器件。测试表明,红色荧光粉能够显著改善发光器件的色温、显色指数等照明品质,在保持白光的同时能够减少光谱中的黄绿光部分,从而缓解眩光效应。     

A design-oriented approach for managing colored light sources in lighting design software

In the last decade, the extensive introduction of LED lighting sources has brought elements of innovation to interior lighting design in terms of color. Besides the new tunable white LED source, lighting is no longer exclusively white; indeed, colored lighting has entered the design practice thanks to the positive effects on people's health and mood. Unfortunately, this element of lighting innovation, color, cannot be computed correctly in commercial lighting design software. These computations are based on the assumption that light is only white or defined in terms of RGB triplets in the relative digital color space of computer graphics, which does not have a physically correct relationship with the actual spectral power distribution (SPD) of luminaires. In this paper, attention is focused on a practical design-oriented approach for describing luminaires in lighting design software that also considers the real SPD and the luminous intensity distribution. The focus is on information available to lighting designers who do not have a laboratory to measure light sources and luminaires. This information could be available in online datasheets or as a Cartesian graph from luminaires and light sources manufacturers. Following this approach, a set of functions is proposed that can be easily implemented in lighting design software to improve light sources' color management and allow lighting designers to add SPD data to luminaires.     

Chromaticity changes of inorganic pigments in Chinese traditional paintings due to the illumination of frequently‐used light sources in museum

Optical radiation can cause permanent damage to the color of Chinese traditional paintings, which have extremely high responsivity in the museum illumination. In order to obtain quantitative influence laws of artificial illumination on inorganic pigments in Chinese traditional paintings and provide basis for choosing light sources, a long periodic illumination experiment was carried out to examine how prolonged exposure of three light sources (tungsten halogen, metal halide and white light emitting diodes), frequently‐used in museums, affect the chromaticity of five inorganic pigments [azurite (blue), cinnabar (red), orpiment (yellow), ancient graphite (black), clam shell powder (white)], commonly used in Chinese traditional paintings. Through the experiment, we found that the illumination causes a color change to inorganic pigments, and the degree of which is related to the photochemical stability of pigments and the high energy shortwave radiation in the light source spectrum. We also obtain the color change laws of the five pigments and the quantitative relationships of color damage for different painting types. These results can provide data basis for related research on Chinese traditional painting illumination and choice basis for light sources in museum lighting designs.     

汽车涂装线照明的设计及应用

主要介绍了涂装车间照明的种类及形式。以光的基本特性为基础,结合涂装各类工位对照度、色温、显色性等照明特性的需求,分析涂装线照明的设计及应用。     

An ergonomic study of visual optimization by light color managements

Light‐emitting diodes (LEDs) have the advantage of controllable light colors and provide the optimal lighting quality against various color attributes required in different environments. However, from the humanized design point of view, beside satisfying physical demands of people, it is also important to achieve satisfaction. With a good match between the LED lighting equipment and ambient colors, the space imagery that complies with psychological needs of human beings can be found. This is expected to become a new market direction for future lighting. In this study, the LED light source feature of adjustable correlated color temperature is used to match wall colors of typical commercial spaces and for the investigation and analysis of the impact of colors of light sources and environments on human beings. The measures of mental and subjective feelings of a group of people under various circumstances have also been investigated. Multivariate analysis of variance has been conducted on three color temperatures of light sources, six wall colors, and measures of five emotion adjectives, and the correlation between these three variables has been further investigated. © 2014 Wiley Periodicals, Inc. Col Res Appl, 41, 72–84, 2016     

Optimization of LED‐based light blendings for object presentation

This study looks at the perceived quality of light‐emitting diode (LED)‐based lighting of various colors. The objective was to find out whether LEDs could provide better (i.e., more relevant and acceptable) lighting than that which is obtained with standard halogen or fluorescent sources. The perception of objects was assessed under different lighting schemes. Subjects were invited to add red, cyan and/or amber to white LED‐based light to match the halogen and fluorescence rendering on specific targets: a color chart and a painting. They were also asked to rate the difference between the two, and to express their preference. The results obtained for the perception of LED‐based lighting were quite positive. Color blendings of LED light were found to provide illuminated situations similar to halogens or fluorescent sources. These blendings were well accepted, and indeed often preferred, although the color rendering index (CRI) was always low. This indicates that the CRI as it stands is inadequate to characterize the color rendering of solid‐state light sources, and needs to be updated. LED‐based lighting systems seem to have considerable potential for use in shops and display units, where they may well outperform existing lighting systems. © 2009 Wiley Periodicals, Inc. Col Res Appl, 34, 310–320, 2009     

Why only blue in the traditional architecture of western Himalaya,India?

The local environment defines the traditional designs and color of buildings in remote wilderness areas. Color, an integral element of the traditional architecture, is related to the culture, experience, perception, and beliefs, which forms a part of the traditional knowledge of the user. Some ethnic groups have been using some specific color patterns in their houses for generations, which have been carried forward in their traditions and customs. Recognizing this, a study to document the color preference and motivations for the preference of specific colors by an ethnic community residing in the interior valleys of western Himalaya was conducted. By group discussions, 13 indicators, which further merged into five motivation categories, were identified. Semistructured interviews (n = 159) were conducted to assess the perception of selected ethnic groups toward color preference. This study reveals that color preference in architecture is influenced by psychological and sociocultural reasons that vary with gender and age classes.     

Designing white‐light LED lighting for the display of art: A feasibility study

When displaying art, several criteria must be balanced when designing illumination including the artist's intention, damage, energy efficiency, viewing experience and understanding, and for commercial galleries and sales. The most common lighting for art includes natural daylight and incandescent spotlights. Neither source is optimal for all criteria; thus there is considerable interest in the use of white‐light light‐emitting diode (LED) lighting. A feasibility study was conducted to address two questions. First, was it possible to design a three‐primary LED source that yielded the same color rendering as common museum lighting? Second, could one design the lighting to achieve specific color appearance attributes? Three‐primary lights using a Gaussian function were optimized matching the chromaticity of D65 and minimizing color differences for a set of acrylic dispersion paints. The optimal wavelengths depended on bandwidth. Lights were also optimized that either maximized or minimized average chroma. A set of real LEDs was selected that produced similar results when evaluated computationally. A source that increases chroma may be useful when used to illuminate works of art with high light sensitivity: very low illuminances are necessary and such a source will compensate for the reduction of colorfulness and visual clarity. A source that decreases chroma may be used to render art in similar fashion to low‐light conditions such as churches and caves. In general, white LED lighting is advantageous for art conservation because they do not emit UV and IR radiation and their visible radiation is reduced when compared with their continuous spectrum equivalent. © 2010 Wiley Periodicals, Inc. Col Res Appl, 2011     

An interior design exhibition: An assessment of color scheme preferences and the emotional states of students

Color is an essential factor for perceiving objects and their interaction. There are many alternatives to color selection in interior design. Colors can be selected according to a user, physical characteristics of the space or a concept. In this context, research has been conducted on the interior color scheme preferences and emotional states with university students. It contains the findings obtained during an interior design exhibition, which was organized at the interior design department of the university. This exhibition was organized for sampling interior color information, selection methods, and using forms. For the exhibition, to be able to observe the changes in the perception of space and the effects of the color, the visuals were arranged according to different color selection methods in the same space. A survey was conducted during the exhibition to examine color scheme preferences and the relation with emotional states of students on interior designs. In the survey, students were asked whether they would prefer or not each interior space and which emotional state is expressed for each visual separately. The statistical analysis was made, and according to the answers given in the survey, comparative results appeared. It is concluded that the students who participate in the survey have meaningful relationships on the spatial color preferences, and differences are determined in emotional states.     

Sensory and Technological Evaluation of Margarines With Reduced Saturated Fatty Acid Contents Using Oleogel Technology

Margarines and spreads contribute greatly to the intake of saturated and trans fats in the diet. Therefore, the objective of this work was to produce margarines using the oleogel technology and to verify the physical, thermal, oxidative, and sensorial properties of this product during six months of shelf life, comparing it with commercial margarine. When compared with commercial margarine, the oleogel margarine showed similar color results. Due to the different structural shape, the results of microstructure and the melting curve were differentiated, but this indicated a structure more resistant to temperature oscillations and an overall softer product. However, the sensorial difference between the samples was easily detected by the consumers, mainly with respect to the parameters of taste, texture, and overall impression. It was concluded that it is possible to produce margarines using the oleogel technology, which display good physical properties, similar shelf life, and improved nutritional characteristics.     

异军突起的陶瓷金属卤化物灯探密

金属卤化物灯(金卤灯)是一种比较先进光源,寿命长,光效高、显色性好。和LVD无极灯性能相似,只是发光源理不同。陶瓷金卤灯其高超性能如高光效、高显色和长寿命已为人们所认同,因此受到照明业界的重视。针对节能减排是陶瓷金卤灯的最大优势和亮点,分析了陶瓷金卤灯中金属卤化物的循环原理,论述了陶瓷金卤灯是一种高技术产品,阐述了光效、显色性和寿命使陶瓷金卤灯成为节能主力,指出了高显色性使陶瓷金卤灯成为道路照明的最佳光源。     

Influence of lighting conditions on the appearance of typical interior materials

Two studies investigated how lighting influences perception of various materials. Experiment 1 focused on preferences of cold or warm light. Participants' task was to indicate preference for either coolish or warmish light for 20 different materials. The selection included materials typically used for wall or floor of interior spaces. Different hues and surface characteristics were present. Specifically two materials of blue color (cold hue) were preferred in a cold light while red carpet (warm hue) and synthetic turf materials were preferred in warm light. This latter choice was explained by automatic reference of synthetic turf to the appearance of natural grass. There were no clear light source preferences for other materials. Experiment 2 explored how the same 20 materials are evaluated under LED lighting in comparison to three other lighting situations (halogen lamp, high‐intensity discharge lamp, and compact fluorescent lamp). The results of this explorative study were not conclusive. The materials chosen for this experiment differed greatly in their structure and optical properties. In conclusion, light influence on the evaluation of materials needs systematic investigation in future research. © 2013 Wiley Periodicals, Inc. Col Res Appl, 40, 50–61, 2015     

Color research in architectural education—A cross-cultural explorative study

This study investigates the knowledge of architectural students about perceptual and psycho-physiological aspects of color, color nomenclature, existing myths and beliefs, and how color is used in their everyday work in the studios. Data were collected mainly by means of questionnaires, to first- and final-year students in five schools of architecture: three in Sweden and two in the United Kingdom. The results were analyzed for each country and educational level, and comparisons made between them. The findings show there is a severe lack of knowledge about color research in both countries. Reading color literature and attending lectures or conferences was rare. However, most participants reported positive attitudes toward color research, especially studies of color perception and color preferences. Knowledge of the Natural Color System (NCS) and British Standard (BSI) was poor, and only a handful of the respondents knew the theoretical basis of the systems. Most of the students complained about the lack of coverage of the subject area in lectures, seminars, or studio work, with very little theory and only few practical exercises. Because students perceive color design as their own future responsibility and basic design education seems to be the main source of color information, the problem of this deficient knowledge should be seriously addressed by researchers and educators. The results suggest ways of improvement and list the most appropriate and preferred methods of communicating research on color. © 1998 John Wiley & Sons, Inc. Col Res Appl, 23, 328–334, 1998     

Global color impressions of multicolored textured patterns with equal unique hue elements

A global color impression from a multicolored textured pattern can be identified. It is not clear, however, how such a single color impression can be determined from the elemental colors of the multicolored textured pattern. To investigate this question, two hypotheses were evaluated. The first hypothesis is that a single color impression is determined by the colorimetric average of the elemental colors in the textured pattern (colorimetric average hypothesis). The second hypothesis is that the impression is influenced by the color appearances of the elemental colors in the textured pattern (color appearance hypothesis). Using an asymmetrical color matching method, the authors obtained single color impressions for random‐dot textured patterns consisting of two colors with the same unique hue and brightness but each with a different saturation. Our results showed that the matched colors were not located on the line connecting the two elemental colors of the pattern, but rather were on the curved unique hue loci line. Furthermore, the chromaticities of the matches shifted toward a higher saturation than the colorimetric averages. These results support the color appearance hypothesis and suggest that a single color impression from a multicolored textured pattern is determined by a mechanism that integrates the color appearances, i.e., hue, saturation, and brightness (or lightness), of the elemental colors in the pattern. In addition, it seems that the integration of the color appearances is not a simple process, because the apparent saturation of the color impression was higher than that of the colorimetric average and the average of the chromaticities of the colors in the pattern. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 267–277, 2007     

Quantifying variations in personal color spaces: Are there sex differences in color vision?

We report a search for group differences in color experience between male and female subjects, focusing on the relative prominence of the axes of color space. Dissimilarity data were collected in the form of triadic (odd‐one‐out) judgments, made with the caps of the D‐15 color deficiency test, with lighting conditions controlled. Multidimensional scaling reduced these judgments to a small number of dimensional‐weight parameters, describing each subject's sensitivity to color axes, i.e., how much each axis contributes to the inter‐color dissimilarities perceived by each subject. Normal trichromatic subjects in two age bands were examined, teenagers and university students, and in both cases males placed significantly less weight on a ‘red‐green’ axis, and more on ‘lightness’. We consider the implications and possible explanations. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 128–134, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10232     

Combustion synthesis of multicomponent ceramic phosphors for solid state lighting

About 50% of the world’s need for lighting is provided by artificial lighting. For over the last decade, the world has witnessed rapid shift from conventional Hg-based lighting to LED-based solid state lighting (SSL). SSL technology extensively uses YAG:Ce³⁺ phosphor for production of white light emitting devices (LEDs). Part of the blue light from the (In,Ga)N LED chip is absorbed by a thin layer of Ce³⁺-doped YAG and is converted into yellow light. The combination of blue and yellow gives a bright white light source with an overall energy efficiency exceeding that of a compact fluorescent lamp. Several soft chemical routes have been explored for synthesis of YAG but were discarded due to their complex nature, high cost for the industrialization, phase impure materials, etc. In this paper we describe rapid one-step modified combustion synthesis of YAG:Ce³⁺ and related phosphors carried out at 500°C using a mixed fuel. Photoluminescence spectra of YAG:Ce³⁺ and LED prepared thereof are comparable with those of commercial phosphors.     

卧式清洁型热回收焦炉的照明设计

对卧式清洁型热回收焦炉各部位的照度作了说明,对照明要求、焦炉照明的光源、照明电器附件以及照明灯具的选择进行了分析,确定了焦炉照明设计的参数。同时,对焦炉照明的供电系统、照明配电装置及灯具的选择、照明光源的控制进行了系统的说明。     

Affective matches of fabric and lighting chromaticity

This study investigates the impact of lighting colors on subjective judgments of fabric: in particular, whether the influence of lighting varies depending on fabric types and color combinations. We conducted two visual assessments. In Study 1 (N = 44), eight illuminants and six types of fabric were presented as cloth stimuli. Derived from the literature review, four sets of adjectives (humble-luxurious, cool-warm, old-new, and not preferred-preferred) were used as metrics. In Study 2 (N = 41), five sets of fabric color combination swatches were assessed under lighting conditions that were identical to those of Study 1. Three bipolar scales (ordinary-characterful, classic-modern, and soft-rigid), were employed from factor analysis along with three unipolar scales (luxurious, preferred, harmonious with lighting). The results showed that hue characteristics of lighting and cloth types influenced participants' perceptions of the fabric. Overall, white lighting with 4000 K was the most preferred and luxurious lighting across various types of clothes, while a pinkish white with 4700 K (duv = −0.0127) was the best matched in every color combination. In addition, there were interaction effects between lighting colors, clothes types, and fabric color combinations with regard to each of the perceptual qualities. This study provides empirical evidence for optimally match lighting colors with fabric in the presentation of fabric goods.