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CIE 075-1988 01-Jan-1988

CIE 075-1988

Spectral luminous efficiency functions based upon brightness matching for monochromatic point sources, 2 degree and 10 degree fields

Commission Internationale de L'Eclairage / 01-Jan-1988 / 30 pages
ISBN: 9783900734114

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Description

In CIE 41-1978 a difference was clearly shown to exist between the luminous efficiency function of the CIE, V(lambda), and the function obtained by the direct heterochromatic brightness matching method, the efficiency of the latter being much higher than that of the former at both long and short wavelengths when both functions were normalized at 570 nm. 

This Technical Report summarizes spectral luminous efficiency functions based on heterochromatic brightness matching for point sources, 2° and 10° fields. Their averaged functions are derived with the intention that they be used to evaluate the luminous efficiency for the brightness of monochromatic lights. These functions could be used as the basis for further work to evaluate light sources with compound spectra. 

The spectral luminous efficiency function for a point source may be adequately represented by the Judd modified V(lambda) function. 

The spectral luminous efficiency functions for the brightness of a 2° field and a 10° field at photopic levels are different from the CIE V(lambda) function and are tabulated in the Technical Report. These functions should be used only to evaluate the luminous efficiencies of monochromatic light sources in terms of their brightnesses. Further work utilizing these functions is required to evaluate lights with compound spectra with allowance for additivity failure. 

CIE 75-1988 is a Technical Report written in Englishi with a short summary in English, French and German. It consists of 20 pages with 6 figures and 8 tables.

CIE 074-1988 01-Jan-1988

CIE 074-1988

Roadsigns

Commission Internationale de L'Eclairage / 01-Jan-1988 / 148 pages
ISBN: 9783900734107

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(1 file, 1.8 MB)
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Description

The purpose of this Technical Report is to provide information that will be relevant to an understanding of roadsigns for road traffic guidance. The report is restricted to matters that are of direct concern to the road user, and it is not concerned with any engineering aspects of signs. 

The first part of the report gives a review in general terms of subjects related to the visual effectiveness of signs. The chapter on information processing demonstrates the complexity of the traffic situation and the driving task. The discussion of four aspects: conspicuity, legibility, comprehensibility and credibility lead the user of the report to a general understanding of all aspects required for a user's perception of signs. 

Many investigations have been made into the factors likely to influence the perception of road signs. An extensive chapter discusses these particular roadsigns aspects as seen from a practical point of view. In this chapter again, the four aspects of conspicuity, legibility, comprehensibility and credibility are shown to be basic. 

Variable message signs (VMS) are the subject of a separate chapter. While the development of these signs is still progressing a state-of-the-art is provided. In the last section of the report a number of different subjects are discussed, including retroreflection, influence of environmental conditions, and the maintenance of signs. 

The publication contains 144 pages, 36 figures and 15 tables.