Description

Currently there is considerable effort within the LED industry and the community who use LEDs to standardise on LED characterisation and measurement. CIE TC 2-34 LED Measurements completed its report on the subject (published as CIE 127-1997 Measurement of LEDs). The CIE 1997 Workshop and Symposium, held on 22-25 October 1997 at the CIE Central Bureau, Vienna, Austria, introduced the CIE recommendations on LED measurements and dealt with the underlying radiometric, photometric and colorimetric measurements. Health aspects of LED radiation were also discussed. The goals of the meeting were:

to introduce the recommended CIE method for characterising LEDs, to share information on the technical content and status of projects involving the characterisation of LEDs, to identify areas where existing/proposed industrial methods are divergent and to initiate discussion towards resolution, to identify areas requiring new technology or knowledge and to recommend needed activities of CIE and industry to provide the necessary solutions.

Papers were read on the following subjects:

• * New LED technologies
• * Industrial measurements
• * Safety issues of LEDs and other light sources, eye hazards
• LED lighting products, the use of LEDs in modern lighting applications
• Measuring new LED products, laboratory and industrial measurements
• LED measuring devices.

The Proceedings contain the text of the 12 papers read as well as a report on the roundtable discussions. The Publication consist of 85 pages.

Description

The Great Britain National Committee of the CIE together with the National Physical Laboratory held a conference on Visual Scales: Photometric and Colorimetric Aspects at the NPL, Teddington on 24-26 March 1997. The Proceedings of this meeting are available from the CIE Central Bureau as CIE x012-1997.

The contributions contained in the Proceedings cover two main topics: Colour Scales (10 papers) and Photometric Scales (9 papers).

The introductory paper in the Colour Scales section was presented by A. Robertson and gives an overview of colour appearance models and colour difference equations. Other contributions in this section include a paper by M.R. Luo on the testing of colour appearance models and one by K. Witt on the scaling of colour difference beyond threshold. The proceedings of two workshop/discussion groups are reported, one dealing with the question of instrumental versus visual colour measurement and the other with the photopic luminous efficiency function.

In the section on Photometric Scales, most of the papers dealt with mesopic photometry. The section starts with a paper from P.W. Trezona on methods of mesopic photometry. Also featured, among others, are contributions by F. Vienot, M.S. Rea and J.L. Barbur, together with their respective teams of co-workers, dealing with visual performance in the mesopic range. There were two workshops in this section, covering the question of performance and conspicuity and of measurements in the mesopic region.

The publication summarizes the present state of knowledge with regard to colorimetric and photometric scales and points out that, in mesopic photometry as in the photopic case, it is necessary to distinguish between the requirement for a brightness or a conspicuity matching criterion.

The Publication consist of 81 pages.