CIE Draft Standard CIE DS 008.2-2000 Lighting of Indoor Work Places
Good lighting will create a visual environment that enables people to see, to move about safely and to perform visual tasks efficiently, accurately and safely without causing undue visual fatigue and discomfort. The illumination may be daylight, electric light or combination of both. Good lighting requires equal attention to the quantity and quality of the lighting. While the provision of sufficient illuminance on the task is necessary, in many instances the visibility depends on the way in which the light is applied, the colour characteristics of the light source and
surfaces together with the amount of glare the system gives. In this standard opportunity was taken to specify for various work places and task types not just the illuminance but also the limiting discomfort glare and minimum colour rendering index of the source. Parameters to create comfortable visual conditions are proposed in the body of this standard. The recommended values are considered to represent a reasonable balance, having regard to the requirements for safe, healthy and efficient work performance. The values can be achieved with practical energy efficient solutions. Lighting requirements for indoor work places of a wide range of working environments are enumerated in 31 sections and numerous subsections in this Draft Standard, they include many areas of industry, agriculture, service, education, health care, entertainment, etc. The Draft Standard does not explain how lighting systems or techniques should be designed to optimise solutions for specific work places. This may be found in the relevant CIE guides and reports.
The draft standard has been sent to National Committees for comments and sales by interested parties. It is still subject to changes and may not be referred to as a CIE standard. When approved by CIE NCs, it will be published as a CIE Standard and later on eventually as a joint standard with ISO or IEC.
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Guide to the Lighting of Urban Areas
CIE 136-2000 ISBN 3 900 734 98 4
The purpose of this guide is to supplement the lighting recommendations and standards for roads and areas of public use as detailed in the Publication CIE 115-1995. It replaces CIE 92-1992: Guide to the lighting of urban areas.
The recommendations cover the effect of light on night time crime and suggests lighting requirements for residential roads and community areas, industrial roads, central business districts and malls, pedestrian paths and access facilities and cycle tracks.
In addition to proposing levels of luminance and illuminance the recommendations consider aspects such as modelling of people and structures within the environment, the effects of glare and sparkle, suitability of light sources as far as colour appearance and colour rendering are concerned, the effect of the lighting on the environment and the general aesthetics of the lighting equipment used.
This publication is written in English, with a short summary in French and German. It contains 38 pages with 5 figures and 11 tables, and is readily available at the CIE National Committees or the CIE Central Bureau in Vienna.
Press Release: Proceedings of the CIE Symposium '99 "75 Years of CIE Photometry"
CIE x18-1999 ISBN 3 900 734 96 8
The 1999 Symposium of the CIE was held at the Hungarian Academy of Sciences, Budapest, between 30 September and 2 October 1999, celebrating the 75th anniversary of the CIE photometric system. Papers dealt with the present photometric system, and discussed its shortcomings and possible extensions.
The presented papers and discussions made it clear that the 75 year old photometric system is still the internationally accepted basis for all visually significant light measurements. It defines one of the base units of the SI system, the candela, and as such it should have a permanent status also in the future. Contributions pointed out, however, that since 1924 great progress has been achieved that found only partly its way into CIE recommendations and standards. By now it is clear that one has to differentiate between foveal vision photometry, to be used when it is important to see and recognise small details, and a photometry that can help illuminating engineers to describe parafoveal vision, brightness perception in the lit environment and mesopic vision.
An introduction was presented by Dr. Hengstberger, at the time of starting the organization of the meeting Director of CIE Division 2 and now Vice President for Publication. Highlights of the meeting were: Professor Valberg, one of the leading scientists in vision research, described underlying vision research that makes the difference between flicker photometry based V(lambda) and opponent colour channel influenced brightness perception understandable. Dr. McGowan's paper discussed the application of photometry in lamp industry. Prof. Rea dealt with the applicability of V(lambda) based photometry for foveal recognition of tasks, also in the mesopic range, and possible extensions for parafoveal vision, where at mesopic levels a photometry based on a 10 degree observer with rod participation seems to be necessary. Photometry is important in interior design, this question and some of the necessary extensions of the present photometric system to cope with the requests interior designers have were dealt with by Prof. Loe. Papers by Dr. Blevin and Dr. Wallard explained the interaction between CIE and the Meter Convention and how new scientific results could find their way into the system of international units and measures. Dr. Walraven reported on the progress CIE TC 1-36 made to recommend a fundamental chromaticity diagram, and to provide data for the extension of the V(lambda) function into the infrared. Dr. Sagawa, Director of CIE Division 1 showed in his closing paper the vision of a future photometer, which is an image photometer, where you can switch among a number of evaluation functions, depending on the actual task to be checked.
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CIE Collection 1999: Vision and Colour, Physical Measurement of Light and Radiation
CIE 135-1999 ISBN 3 900 734 97 6
This volume contains short Technical Reports and Research Notes prepared by various Technical Committees and Reporters within CIE Division 1 and 2.
135/1: Disability glare On the basis of a preceding theoretical analysis of experimental data on disability glare published in CIE Collection (Vos and Van den Berg, 1997), resulting in a complete glare equation covering the full 0° to 100° glare angle range, three simplified glare equations are presented, each of them defined for a more restricted glare angle domain. This ensemble of three equations together is recommended to define a CIE Standard Glare Observer; the most simple one, the Age Adapted Stiles-Holladay Equation, will suffice for most circumstances of daily practice.
135/2: Colour rendering, closing remarks The CIE "Test method to calculate a colour rendering index" has a long and complicated history. After first publishing a method in 1965 and updating it in 1974, it was soon realised that further amendments would be necessary. A TC worked on the subject in the 1980s, but had to be closed without any definite recommendation due to disagreements among the TC Members. A second trial was started after the 1991 Quadrennial Meeting. This TC worked - under various chairmen - for about six years, but again it had to be closed without producing a definite recommendation, although this time TC Members agreed in a number of questions. This report summarizes those items where TC Members could agree and highlights also those questions where no consensus could be reached. To the latter category two groups of questions belong: items where it is hoped that CIE will come up very soon with further recommendations that should be incorporated in a colour rendering calculation (e.g. new chromatic adaptation transformation) and items where a political decision of the lamp manufacturers is needed, as a change in the calculation method necessarily will favour one lamp spectrum compared to that of an other. The present closing remarks document summarizes the items discussed by the TC during the past decade, states those items where a consensus could be formed and pinpoints questions where further research is needed to reach consensus.
135/3: Virtual metamers for assessing the quality of simulators of CIE illuminant D50 (Supplement 1-1999 to CIE 51-1981) CIE 51-1981 describes a method of assessing the quality of simulators of CIE illuminants D55, D65, and D75 (various phases of daylight), for colour measuring instruments, visual appraisal and matching of colours. The spectral power distribution of the simulator is measured and the departure from the ideal distribution is computed, in terms of chromaticity differences between virtual metameric pairs that match under the ideal CIE illuminant. CIE illuminant D50 is simulated for use in photography and colour printing. This supplement provides the virtual metamers needed to apply the method of assessment to D50 simulators.
135/4: Some recent developments in colour-difference evaluation A compressed overview is given of developments in colour-difference evaluation that trace back to the early beginnings by MacAdam. The correlation of colorimetric measures of coloured samples with judgements on small colour differences follows normal statistics, but in a three-dimensional space. A wide diversity of experimental conditions in investigations of the colour-difference effect made comparisons of different studies troublesome. Some external influential factors could be identified. Recently developed data sets resulted from much better control of experimental conditions. They form a new basis for deriving colour difference formulae. The CIE is the international body to encourage field research for optimising new colour-difference formulae. The various stages for recommending formulae and exchanging extensive investigation documents make a close link between practitioners and theorists, however, in general industrialists have a faster response. Nonetheless, the CIE still remains the mother-body for international discussion and agreement. Recent developments in colour-difference evaluation show an acceleration of the work of CIE TCs. Their studies first improved the CIELAB-formula, and second now try to fill the gap between the CIE94 and the older CMC(l:c) solutions. A new idea is introduced to optimise the formalism of a formula not at the components of differential terms, but at the co-ordinates which keeps the vector definition of colour-difference as in the CIELAB-formula. An international discussion is proposed on this aspect as a forthcoming step to further improvement of colour-difference evaluation.
135/5: Visual adaptation to complex luminance distribution One of the most important and difficult tasks in evaluation of perceived brightness in everyday circumstances is to assess what level the visual system adapts to. Especially, this is an inevitable process when putting the new photometric system into practice. In the present report, several
studies are reviewed, and tasks and problems of the prospective TC are discussed. Although many studies of brightness perception are potentially related to the matter of adaptation level, we can find no literature in which the issue is discussed explicitly. All what we can do now is to encourage investigators to carry out research concerning the level of visual adaptation not only in experimental conditions but also in natural and complex environments.
135/6: 45°/0° Spectral reflectance factors of pressed polytetrafluoroethylene (PTFE) powder (Reprint of NIST Technical Note 1413) Pressed polytetrafluoroethylene (PTFE) powder is used for 45°/0° reflectance factor standards. The radiometric and spectrophotometric measurement community such as the Council for Optical Radiation Measurements (CORM) has demonstrated the need for such a standard and its application to quality control and quality assessment. This publication briefly describes the instrumentation used for the 45°/0° spectral reflectance factor measurements of pressed PTFE powder from 380 nm to 770 nm. Also, the variations of 45°/0° reflectance factor with sample preparation and materials are discussed. The expanded uncertainty at a coverage factor of two for the 45°/0° reflectance factors of pressed PTFE powder ranges from 0,009 to 0,017.
The publication contains also abridged abstracts of CIE Publications prepared within Division 1 and 2. These reports are written in English, with short summaries in French and German. The publication contains 78 pages and is readily available at the CIE National Committees or the CIE Central Bureau in Vienna.
A printed Proceedings and a CD-ROM containing all the papers in a searchable form are available at the CIE Central Bureau, Kegelgasse 27, A-1030 Vienna, Austria, e-mail: ciecb@ping.at.