LANGUAGE OF LIGHT

LANGUAGE OF LIGHT OF

With new publications, a digital version of its ‘International Lighting Vocabulary’, a free guide on visual impairment and a virtual conference in September, the CIE has been keeping busy during the past year

By John O’Hagan

As most ILP members will probably be aware, CIE-UK is the UK national committee of the International Commission on Illumination or CIE (from the French ‘Commission Internationale de l´Éclairage’).

The ILP is a sponsoring organisation member of CIE, and therefore this is an update on some of the CIE’s latest, and upcoming, activity during what has been a challenging 12 months.

A significant recent publication from CIE has been the latest edition of the International Lighting Vocabulary. In the world of development of technical publications, terminology is where it all begins.

This publication provides a set of agreed definitions and terms for concepts common to a field, reducing the level of ambiguity associated with words and sentences. Before starting work on technical documents, experts first must agree on the terminology, so that everyone understands the concepts which are referred to.

This is particularly important when disciplines come together to discuss topics that overlap their fields. Light and lighting, both science and application, brings together psychology, physiology, photobiology, vision science, engineering, physics, horticulture, and architecture.

In the CIE, terminology has therefore always been a key subject. For example, a century ago, in 1921, attendees at the 5th Session of the CIE began to discuss the publication of a lighting vocabulary.

CIE update

t A visually impaired woman enjoying a park in London.

The CIE is making its publication Lighting for older people and people with visual impairment in buildings available free of charge to its national committees until February 2022

DIGITAL ‘INTERNATIONAL LIGHTING VOCABULARY’

The first edition of the International Lighting Vocabulary (ILV) was published in 1938. Further editions followed in 1957, 1970 and 1987. The 1987 edition was adopted by the International Electrotechnical Commission (IEC) for integration into its International Electrotechnical Vocabulary (IEV). In 2011 CIE published a new, completely revised edition of the ILV, the first time as an International Standard, CIE S 017 ILV: International Lighting Vocabulary. The second edition was published in late 2020 with many new terms, reflecting advances in technology for LED lighting and imaging technologies – the latter of which has its own new section.

The aim of the ILV is to promote international standardisation in the use of quantities, units, symbols and terminology related to the science and art of light and lighting, colour and vision, metrology of optical radiation over the ultraviolet, visible and infrared region, photobiology and photochemistry, and image technology.

This vocabulary provides the definitions and essential information necessary for the understanding and correct usage of the terms included. It does not give extensive detail or explanations of the application of these terms; such information, relevant for experts in each specialised field, is available in the Technical Reports and International Standards published by the CIE.

To support CIE’s aim to promote clear communication, good science, and international standardisation in the use of quantities, units, symbols and terminology, the terms and definitions from CIE S 017:2020 have been made accessible online in an electronic version of the ILV, the e-ILV (http://cie.co.at/e-ilv). This therefore now gives everyone free access to the definitions of CIE’s terminology standard.

For those who require the complete ILV, it can be purchased through the CIE webshop. There is also a short video announcing the publication at https:// vimeo.com/493333848.

TWO NEW PUBLICATIONS

There have also been two other new publications brought out by the CIE. These are: 1) Photometry of curved and flexible OLED and LED sources (CIE 242: 2000). The trend for high-tech products is towards the capability of flexibility, for example flexible lighting, displays, cell phones, batteries, sensors, memory, solar cells.

Flexible products can be light, thin, break-resistant, and offer more creative freedom for the designer. It is not only for fun and fashion, but also because flexible products are practical.

For instance, rollable displays can reduce the limitations of space and add further convenience for portable digital electronic products. As it is thin and light, flexible lighting can be integrated with clothes to increase safety at night. Flexible sources also allow greater variety in lighting design.

Because of their power to enrich our life, more and more research institutes are working on developing flexible materials and products. As flexible products become more common, measurement research is needed to support the industry.

The report therefore describes the methods of measuring photometric and colorimetric quantities for curved sources and gives guidance for the determination of measurement uncertainties. The measurement quantities include luminance, luminous flux, colour, reflectance, and viewing angle.

2) Discomfort glare in road lighting and vehicle lighting (CIE 243: 2021). This report provides an overview of the research methods, mathematical models and the variables which are considered to influence discomfort glare. The report describes the difficulties associated with the evaluation and measurement of discomfort glare and the variance in the models.

One aim of the report is to encourage further research on discomfort glare using methods recommended by the proposals raised in this report. Such research will generate a greater body of credible data, thus enabling the development of a more robust model. It is intended to update this report in due course with these additional data and a revised discomfort glare model.

HOW TO ACCESS CIE PUBLICATIONS

UK-based members of the ILP are eligible for the CIE-UK members’ discount for CIE publications, which represents a two-thirds reduction on the list price. A discount is also available for some CIE events.

Please email ILP Chief Executive Tracey White on tracey@theilp.org.uk for the discount code.

Publications can be purchased via the relevant link on the CIE website, http://cie.co.at/

FREE GUIDE ON VISUAL IMPAIRMENT

Furthermore, CIE is making one publication available free of charge to its national committees for a year (until February 2022).

CIE-UK is able to offer this to UK members of the ILP, again by emailing tracey@theilp.org.uk

The free document is Lighting for older people and people with visual impairment in buildings (CIE 227:2017).

This report summarises lighting recommendations on lighting and the visual environment in interior spaces such as offices, public spaces, and residences for healthy older people (defined as people aged 50 years and older) with normal vision, and people with low vision, and implements guidelines described in CIE 196:2011 (CIE Guide to Increasing Accessibility in Light and Lighting) into practical solutions.

The report provides illuminance recommendations, derived from simulations with existing visual models for older people.

It also outlines state-of-the-art of studies on how light helps people with low vision see objects by reviewing recent literature. Finally, it sets out design guidelines for lighting practitioners on how to design appropriate visual environments for people with low vision.

UPCOMING CONFERENCE

The 2021 CIE Mid-Term Conference will be held online from 27 to 29 September, 2021.

The broad theme of the three-day event is ‘Light for life – living with light’.

More details can be found at the conference website: https://malaysia2021.cie. co.at/

UK-based members of ILP will be able to register for the discounted rate using the discount code available, again, from tracey@theilp.org.uk

If you are not based in the UK but are a member of the CIE national committee in your country, you may be able to get a discount code from them.

John O’Hagan is chair of CIE-UK

INTERESTED IN JOINING CIE-UK?

If anyone is interested in joining CIE-UK, please feel free to get in touch with Allan Howard (executive secretary of CIE-UK) at WSP, on Allan.Howard@wsp.com