SLL Jan/Feb 18

Newsletter Volume 11. Issue 1. Jan/Feb 2018

The Society of Light and Lighting

Part of the Chartered Institution of Building Services Engineers

LIGHT READING

LR&T celebrates its 50th volume

SPARKLING PERSONALITY

An illuminating conversation with Ron Arad @sll100

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Editorial

Secretary Brendan Keely FSLL bkeely@cibse.org SLL Coordinator Juliet Rennie Tel: 020 8675 5211 jrennie@cibse.org Editor Jill Entwistle jillentwistle@yahoo.com Communications committee: Gethyn Williams (chairman) Rob Anderson Iain Carlile MSLL Jill Entwistle Chris Fordham MSLL Eliot Horsman MSLL Mark Ingram MSLL Stewart Langdown MSLL Linda Salamoun MSLL Bruce Weil All contributions are the responsibility of the author, and do not necessarily reflect the views of the society. All contributions are personal, except where attributed to an organisation represented by the author.

Copy date for NL 2 2018 is 20 January Published by The Society of Light and Lighting 222 Balham High Road London SW12 9BS www.sll.org.uk ISSN 1461-524X © 2018 The Society of Light and Lighting The Society of Light and Lighting is part of the Chartered Institution of Building Services Engineers, 222 Balham High Road, London SW12 9BS. Charity registration no 278104

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Printed in UK

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Unit C, Northfield Point, Cunliffe Drive, Kettering, Northants NN16 9QJ Tel:01536 527297

As we mark the beginning of a celebratory year for Lighting Research and Technology, there is an inevitable retrospection, a casting of minds back to 1969 when the first issue emerged, a successor to Transactions, from the then Illuminating Engineering Society.

Several aims lay behind it: to bring together all the IES technical communications in one place to elevate both the status of lighting and the IES; to develop a high-quality journal that was more outward looking, reflecting an increasingly globalised lighting industry.

And, of course, to encourage and disseminate research about lighting.

It is the type of publication that is, and should be, in the DNA of the society, at the core of a learned body.

But publications such as LR&T are of necessity esoteric. There are a fair number of lighting specialists who would readily acknowledge that the papers published are above their heads.

Some 17 years ago, Peter Tregenza wrote that the central aim of LR&T was ‘to publish primary papers in lighting research’ but he added that it was also important ‘to provide a context in which new research can be appraised and understood by the non-specialist’. In his evaluation of the history and potential future of LR&T (see p5), Peter Boyce acknowledges that ‘there is little doubt that the former aim has been achieved but the latter has not.

‘Research today,’ he continues, ‘is ever more specialist, so much so that it has become impossible for even the most assiduous reader of the literature to keep up to date with all aspects of a multifaceted subject such as lighting.’

However, there are initiatives to counter this issue, one being LRT Digests, which encapsulate aspects of established research for the nonspecialist. Another aim is to reintroduce the helpful discussions of papers, a feature of LR&T for many years. The publication may be in its 49th year but there’s no sign of waning vigour or resting on academic laurels.

Jill Entwistle jillentwistle@yahoo.com

Current SLL lighting guides

SLL Lighting Guide 1: The Industrial Environment (2012) SLL Lighting Guide 2: Hospitals and Health Care Buildings (2008) SLL Lighting Guide 4: Sports (2006) SLL Lighting Guide 5: Lighting for Education (2011) SLL Lighting Guide 6: The Exterior Environment (2016) SLL Lighting Guide 7: Office Lighting (2015) SLL Lighting Guide 8: Lighting for Museums and Galleries (2015) SLL Lighting Guide 9: Lighting for Communal Residential Buildings (2013) SLL Lighting Guide 10: Daylighting – a guide for designers (2014) SLL Lighting Guide 11: Surface Reflectance and Colour (2001) SLL Lighting Guide 12: Emergency Lighting Design Guide (2015) SLL Lighting Guide 13: Places of Worship (2014) SLL Lighting Guide 14: Control of Electric Lighting (2016) LATEST SLL Lighting Guide 0: Introduction to Light and Lighting (2017) SLL Lighting Guide 15: Transport Buildings (2017) SLL Lighting Guide 16: Lighting for Stairs (2017) Guide to Limiting Obtrusive Light (2012) Guide to the Lighting of Licensed Premises (2011)

Secretary’s column

‘Many of us will not see another LR&T celebration like this again’

Editorial 2 Secretary’s column

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News 4 Uncommon knowledge Marking the 50th volume milestone, Peter Boyce and David Carter look at LR&T’s past, present – and future

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Cutting edge-lighting Young Lighter of the Year Matt Hanbury outlines his solution to the quest for an ultra-thin light source

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All-round brilliance 12 Chris Fordham and Linda Salamoun talk to colourful and highly creative designer Ron Arad about his use of light Surgical precision 15 Colour temperature in medical applications is a key motif in the latest online LR&T papers, discovers Iain Carlile Events 16

You can now register your interest for Young Lighter of the Year 2018 (sll@ cibse.org) if you are under 30 years of age on 11 May 2018. If you are not under 30 then please encourage your colleagues to take part. We’ve had papers on all topics of light and lighting and it doesn’t need to be a research presentation – all aspects of light and the built environment can be included.

The Jean Heap Bursary 2018 is also open to all and again you can register your interest at the email address above.

We will be joining our friends at Revo Media for the Lux Lighting for Transport and Infrastructure conference on 22 February at London’s Cavendish Conference Centre. Keith Miller of GIA Equation, author of the new SLL Lighting Guide: LG15 Lighting for Transport, will be headlining the event.

The one-day conference is free to attend for end users, lighting designers and engineers, and we will also be around in the background to answer any of your queries. More details on the event can be found at www. lightingfortransportandinfrastructure.com

Cover: Smythe Library at Tonbridge School, Kent, winner of best lighting project in the 2017 FX Awards. Lighting by BDP

bkeely@cibse.org For up-to-date information follow us on Twitter @sll100

Hufton + Crowe

Happy New Year to you all. We hope you all had a good festive season and you’re ready to get on with 2018.

This year will see the society mark the 50th volume of Lighting Research and Technology (see p5) with a symposium on the inaugural International Day of Light on 16 May in London. The contributors to the first edition of the 50th volume will present their papers in an accessible way and look at their research in the context of the future of light and lighting application.

We encourage you to book to attend the event – many of us will not see another LR&T celebration like this again and the event will be appropriate for all in lighting design, engineering and research, as well as light and the built environment. The celebration copy of Volume 50, Edition 1 can also be purchased from Sage, and of course all members can download all copies of LR&T, as well as its predecessor, IES Transactions, from the Sage website.

We look forward to this year’s Ready Steady Light at Rose Bruford College in Sidcup, Kent, on Tuesday 13 March.

Bookings are being taken already so make sure you don’t miss out on this opportunity to learn, play, gather, network and deliver stunning designs. All details are on the website and we look forward to another brilliant event.

We will be attending Light + Building in Frankfurt from Sunday 18 March and will meet with the supporters of the society.

Messe Frankfurt will be giving us a number of free entry passes so if you are planning to attend and want a pass or two please do get in touch with me.

The Lighting Knowledge Series, LightBytes goes from strength to strength with a sell-out audience in Dublin in November. The brand new series will visit Birmingham on 25 January, Bristol on 22 February, Newcastle on 26 April,

Glasgow on 10 May and finally London on 7 June. We hope to see many of you in your regions with talks by Les Thomas from Fagerhult, Helen Loomes from Trilux, Steve Shackleton from Zumtobel and Roger Sexton from Xicato. The guest speaker slot is filled throughout the year with input from our digital engineering colleagues. It’s a great day out, super informative and we encourage you all to attend.

You will notice that the AGM Notification is included with the SLL Newsletter and CIBSE Journal (on the back is the information relating to the LR&T Symposium and Volume 50, Edition 1). The AGM will take place on 24 May at the Haberdashers’ Hall, London EC1. As well as the AGM, we will present the annual awards and, of course, the presidential address from Iain Carlile.

Iain was involved in lighting the venue so we all get a chance to see his work.

Contents

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NEWS...NEWS...NEWS...NEWS...NEWS...NEWS...NEWS...NEWS...NEWS...NEWS...NEWS...NEWS...NEWS...NEWS...

Peter Boyce is awarded Lux Person of the Year 2017 Dr Peter Boyce, longserving editor of the lighting industry’s peer-reviewed journal Lighting Research and Technology (LR&T), was named Lux Person of the Year 2017.

Presented at the Lux Awards at the InterContinental – The O2 hotel in London on 16 November, the honour was in recognition of his outstanding contribution to lighting research.

Over a 50-year career in lighting research, Dr Boyce has become a world authority on the interaction of people and lighting. Author of the seminal work Human Factors in Lighting, as well as

numerous papers, articles and book chapters, his insights have informed standards and practices for decades.

He is a Professor Emeritus at Rensselaer Polytechnic Institute in Troy, New York, and a fellow both of the SLL and IESNA. He took up the editorship of LR&T in 2008.

‘It was most fitting to see Dr Peter Boyce receive the 2017 Lux Person of the Year award,’ said SLL president Richard Caple.

‘A person that has contributed so much to lighting and the industry, not to mention the service that he has given to the SLL, he has influenced directly or indirectly most lighting people at some time or another. A highly worthy award winner.’

Year of the Dragon for Ready Steady Light ME

A total of 45 competitors took part in Ready Steady Light Middle East, the second time the event has been held in Dubai. Team Dragon swept the board with all three prizes available – technical, artistic and peer – with their Dance of

BSI honours Bedocs Lou Bedocs has recently been awarded the International Standards Maker award by the British Standards Institution. The award was largely for his work in overseeing the writing of EN 15193, Energy performance of buildings – Energy requirements for lighting.

Bedocs has represented CIBSE on the BSI light and lighting committee ever since CIBSE was formed.

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the Dragon Fly installation (pictured left).

Organisations which took part included Lightitude, Nathan Savage Lighting Design, Osram, Studio Lumen, Light Touch PLD, DPA and Nulty+.

This year’s judges were SLL president Richard Caple, Sakina Dugawalla of Light.

Func, Martin Valentine, now of Ligman, Michael Grubb of Michael Grubb Studio, Jasmeet Bakshi of Messe Frankfurt and SLL secretary Brendan Keely.

The competition was generously supported by acdc, Erco, Ecosense, Feilo Sylvania, Lightitude, Lumascape, Martin Professional ME, Osram, Targetti, Traxon and Zumtobel.

On the lighter side...

Hands up who wants a light fitting made of pond weed? Named Exhale, this part chandelier and part living organism has 70 glass petals of varying shapes that contain a solution of green algae sustained by daylight, LEDs, and a dripfeed of nutrients. Created by Londonbased designer and engineer Julian Melchiorri, it won the 2017 Emerging Talent Medal at the London Design Festival and was on display at the Victoria and Albert Museum. Actually, it could grow on you.

Light source entrepreneur wins YLOTY

Matt Hanbury, founder of Lightly Technologies, has won SLL Young Lighter of the Year 2017. The announcement was also made at the Lux Awards.

Hanbury impressed the judges with his presentation and paper, entitled Ultra-thin Surface Light Sources: picking up where OLED stalled.

Hanbury (pictured centre) received his award from Gethyn Williams of Amerlux (far right). Also shown are SLL president Richard Caple (second left) and Mark Sutton Vane (second from right), who judged on behalf of the Lighting Education Trust (LET). Other judges were Dr Peter Boyce, John Aston and SLL president elect Iain Carlile.

The other finalists were Amir Nezamdoost, who won the Best Written Paper Award for A New Manual Blind Use Pattern for Annual Energy and Daylight Simulation, and Seren Dincel of AF Lighting with her paper, City Lighting in Scandinavia – Design Approach and Methodology.

The final took place at LuxLive, London ExCel, earlier the same day, with each finalist giving a 15-minute presentation in front of the judges.

LR&T 50th volume

Uncommon knowledge Marking its 50th volume, 2018 is a landmark year for Lighting Research and Technology.

Peter Boyce and David Carter look at the publication’s past, present – and future

The past

Above: from A new direction for general lighting practice (Cuttle C, LR&T 2013) Left: the orange cover distinguished it from all other journals

‘Discussions with various bodies indicated a broad level of support for a high-quality journal that was more outward looking, thereby reflecting an industry that was beginning to be more global’ from print to electronic forms of publishing and communication with authors and readers. The status of LR&T was enhanced in 2006 by admission to the Science Citation Index Expanded (SCIE) and endorsement by the CIE. Despite these changes in methods and status, some aspects of LR&T have changed very little since 1969. All papers are still peer reviewed, commercial bias is frowned upon and the orange cover is still evident.

Incidentally, the orange cover was chosen on the basis that it stood out from all the other journals then received by the IES. While details of production are interesting for those involved, for readers it is content that really matters. An examination of past issues shows that there are some topics that have been studied for many decades, others that have disappeared and then returned, others that once were dominant but now are absent, and yet others that are emerging. The forces that determine what topics are the subject of research are advances in technology, problems in lighting practice, new knowledge about the effects of light exposure, new societal concerns, and, of course, money.

One topic that has persisted for many years is discomfort glare. Partly this is because little progress has been made in understanding the mechanisms behind it and partly because new light sources have been developed that cause new problems of discomfort, the latest being LEDs. Another persistent topic has been the calculation and delivery of daylight and its integration with electric lighting. This has been driven by concerns about energy consumption and developments in daylighting technology and control systems. @sll100

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The first volume of Lighting Research and Technology was published in 1969. Before that the Illuminating Engineering Society of Great Britain, the distant ancestor of the Society of Light and Lighting, had two regular publications, Transactions of the Illuminating Engineering Society, and Light and Lighting, as well as a number of ad hoc publications including IES Technical Reports and IES Monographs. The issues of Transactions from 1936 to 1968 are now available on the LR&T website. The other three publications have almost entirely vanished into the mists of time.

The decision to replace Transactions with a new journal to be called Lighting Research and Technology was driven by George Cole, then secretary of the IES, ably aided by Dr Eric Harper. The basic motivation was to bring together all the IES technical communications in one place and thus to enhance the status of lighting and the IES. Discussions with the lighting industry, universities and the CIE indicated a broad level of support for a high-quality journal that was more outward looking, thereby reflecting an industry that was beginning to be more global.

The work involved in producing such a journal was not negligible because LR&T was then self-published by the IES. Papers were typewritten, communication with authors and readers was by post and subscriptions were paid by cheque.

There were no personal computers, no internet, no worldwide web and no search engines.

Probably the most significant change in the production of LR&T since 1969 was the move to a professional publisher in 2001.

This move resulted in a change of format and a steady shift

LR&T 50th volume

conditions on visual performance was important for many years but is seldom addressed now. This does not mean performance has ceased to matter, rather that visual performance is well understood and attention has shifted to other aspects of performance such as alertness, cognitive capabilities and behaviour. Other topics have emerged driven by new societal concerns. This is the case for light pollution. Another example is the impact of light operating through the human non-imageforming system. The discovery of a new class of photoreceptor, the intrinsically photosensitive retinal ganglion cell, and the consequent recognition that light can have an impact on human physiology beyond the visual system, has led to a surge of research in this area. Another area of increased interest is the development of better measures of light source colour properties. This has been driven by the potential for narrow band LEDs to create almost any light spectrum Within this waxing and waning of topics, there have been some papers published in LR&T that can be regarded as landmarks. The reference list (right) cites 50 such papers.

This list is our personal choice. No doubt others with different interests would have made different choices but, regardless, the existence of such papers is evidence that over the years LR&T has made a significant contribution to our understanding of the role of lighting in everyday life.

„„ The present

AM, 1970). Centre and above: Investigation of the subjective balance between illuminance and lamp colour properties (Boyce PR, 1977)

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A topic that was present, then disappeared and has now revived is flicker. In the 1970s, flicker was a problem with fluorescent lamps controlled by electromagnetic ballasts. When electronic control gear became available, the problem went away and the topic ceased to be of interest until LEDs became a practical light source.

LEDs have a very fast response time so care is required with the design of the driver if flicker is to be avoided.

One topic that once was dominant but now has largely disappeared is the integration of lighting with the heating and ventilation of buildings. Some topics have not disappeared but have changed their form. For example, the effect of lighting

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Top: Brightness – luminance relationships in an interior (Marsden

At present, LR&T is in good health. Over the past few years the size of each volume has increased, from four to eight issues a year, and the number of pages in each issue has increased from 96 to 128. To some extent this growth has been driven by the number of papers submitted and the number accepted for publication. In 2016, 189 papers were submitted. Of these, 62 were accepted for publication. The submitted papers came from 32 different countries but predominantly China, USA, UK, Spain, Taiwan and Germany.

An important point for many authors is the impact factor of the journal. It is important because being published in a journal with a high impact factor carries more prestige for the author.

The impact factor for a given year is calculated as the ratio of the number of papers published in an issue in the previous two years that have been cited in the given year to the total number of papers published in an issue in the previous two years. The first impact factor for LR&T was released in 2008 and was 0.733. Currently the impact factor of LR&T is 1.784.

An increase in the number of papers being published is not the only facet of the publication that has changed in recent years. Probably the most important is Online First. This is an electronic listing of papers accepted for publication before they appear in print. Being electronic the papers can be published as soon as they are ready and can be cited by quoting their digital object identifier. Access has also widened by the availability on the website of all the issues of LR&T back to 1969, together with the Transactions of the IES from 1936 to 1968 (free to members of the SLL, and at a price to others).

None of this would be possible without the work of a lot of people. The most obvious group is the authors who submit their work for review because without them there would be nothing to publish. If successful, they are rewarded by having their work published, something that is essential for anyone wishing to make progress in academia. If they are not successful, it is

LR&T 50th volume

50 landmark papers in LR&T 1. Saunders JE. The role of the level and diversity of horizontal illumination in an appraisal of a simple office task. LR&T 1969; 1: 37-46.

for assessing daylight in buildings. LR&T 2005; 37: 41-59.

2. Marsden AM. Brightness – luminance relationships in an interior.

LR&T 1970; 2: 10-16.

images. LR&T 2005; 37: 329-341.

3. Lynes JA. Lightness, colour and constancy in lighting. LR&T 1971; 3: 24-42.

luminance data acquisition system. LR&T 2006; 38: 123-136.

4. Jay PA. Lighting and visual perception. LR&T 1971; 3: 133-146.

32. Goodman T, Forbes A, Walkey H, Eloholma M, Halonen L,

5. Cuttle C. Lighting patterns and the flow of light, LR&T 1971; 3: 171-189.

Alferdinck J, Freiding A, Bodrogi P, Varady G Szalmas A. Mesopic

6. Hills BL. Visibility under night driving conditions. LR&T 1976; 8; 11-26.

other applications. LR&T 2007; 39: 365-392.

7. Boyce PR. Investigation of the subjective balance between illuminance and lamp colour properties. LR&T 1977; 9: 11-24.

30. Tuaycharoen N, Tregenza PR. Discomfort glare from interesting 31. Inanici MN. Evaluation of high dynamic range photography as a

visual efficiency IV: A model with relevance to night-time driving and 33. Veitch JA, Newsham GR, Boyce PR, Jones CC. Lighting appraisal,

wellbeing and performance in open-plan offices: A linked mechanisms

8. Waldram JM. A manual of perspective for lighting engineers. LR&T 1982, 14: 65-101

approach. LR&T 2008; 40: 133-151.

9. Tregenza PR, Waters IM. Daylight coefficients. LR&T 1983; 15: 65-71.

A comprehensive and quantitative framework for assessing light

10. Bedocs L, Hugill JR, Lynes JA. Point-by-point illuminance from uplighters. LR&T 1985; 16: 187-192

pollution. LR&T 2008; 40: 201-224.

11. Boyce PR. Movement under emergency lighting – the effect of illuminance. LR&T 1986; 17: 51-71.

savings. LR&T 2009; 41: 261-283.

12. Wilkins AJ, Nimmo-Smith I, Slater AJ, Bedocs L. Fluorescent lighting, headache and eyestrain. LR&T 1989; 21: 11-18.

pressure sodium lighting for outdoor applications. LR&T 2009; 41: 297-320.

13. Adrian W. Visibility of targets: Model for calculation. LR&T 1989; 21: 181-188.

sequence for diffuse daylight. LR&T 2010; 42: 7-31.

14. Littlefair P. Innovative daylighting: Review of systems and evaluation methods. LR&T 1990; 22: 1-17.

38. Miller D, Bierman A, Figueiro MG, Schernhammer ES, Rea MS.

15. Rea MS, Ouellette MJ. Relative visual performance: A basis for application. LR&T 1991; 23: 135-144.

16. Cuttle C. Sumpner’s principle. LR&T 1991; 23: 99-106.

17. Aizlewood CE, Weber GMB. Escape route lighting: Comparison of human performance with traditional lighting and wayfinding systems.

LR&T 1995; 27: 133-143.

18. Cuttle C. Cubic illumination. LR&T 1997; 29: 1-14.

19. McCloughan CLB, Aspinall PA, Webb AS. The impact of lighting on mood. LR&T 1999; 31: 81-88 20. Boyce PR, Eklund NH, Hamilton BJ, Bruno LD. Perceptions of safety at night in different lighting conditions. LR&T 2000; 32: 79-91.

21. Painter KA, Farrington DP. The financial benefits of improved street lighting based on crime reduction. LR&T 2001; 33: 3-12.

22. Carter DJ. The measured and predicted performance of passive solar light pipe systems. LR&T 2002; 34: 22-39.

23. Moore T, Carter DJ, Slater AI. Long term patterns of use of occupant-controlled office lighting. LR&T 2003; 35: 43-59.

24. Vos JJ. Reflections on glare. LR&T 2003; 35: 163-178.

34. Brons JA, Bullough JD, Rea MS. Outdoor site lighting performance:

35. Mardaljevic J, Heschong L, Lee E. Daylight metrics and energy 36. Rea MS, Bullough JD, Akashi Y. Several views of metal halide and high 37. Reinhart CF, LoVerso VRM. A rule of thumb-based design

Ecological measurement of light exposure, activity and circadian disruption. LR&T 2010; 42: 271-284.

39. Plitnick B, Figueiro MG, Wood B, Rea MS. The effect of red and

blue light on alertness and mood at night. LR&T 2010; 42: 449-458.

40. Wen Y-J, Agogino AM. Wireless-networked lighting in open-plan

offices. LR&T 2011; 43: 235-248.

41. Leslie RP, Radetsky LC, Smith AM. Conceptual design metrics for

daylighting. LR&T 2012; 44: 277-290.

42. Rea MS, Figueiro MG, Bierman A, Hamner R. Modelling the

spectral sensitivity of the human circadian system. LR&T 2012; 44: 386-396.

43. Cuttle C. A new direction for general lighting practice. LR&T 2013;

45: 22-39.

44. Clear RD. Discomfort glare: What do we actually know? LR&T

2013; 45: 141-158.

45. Duriscoe DM, Luginbuhl CB, Elvidge CD. The relation of outdoor

lighting characteristics to sky glow from distant cities. LR&T 2014; 46: 35-49 46. Fotios S, Unwin J, Farrall S. Road lighting and pedestrian

reassurance after dark: A review. LR&T 2015; 47: 449-469

25. Rea MS, Bullough JD, Freyssinier-Nova JP, Bierman A. A proposed unified system of photometry. LR&T 2004; 36: 85-111.

47. Schielke T, Leudesdorf M. Impact of lighting design on brand image

26. Cuttle C. Brightness, lightness and 'providing a preconceived appearance to the interior'. LR&T 2004; 36: 201-216.

48. Wilkins AJ. A physiological bases for visual discomfort: Application

27. Boyce PR. Lighting research for interiors: The beginning of the end or the end of the beginning. LR&T 2004; 36: 283-294.

49. Narendran N, Freyssinier JP, Zhu Y. Energy and user acceptability

28. Guo X, Houser KW. A review of colour rendering indices and their application to commercial light sources. LR&T 2005; 36: 183-199

LR&T 2016; 48: 789-809.

29. Nabil A, Mardaljevic J. Useful daylight illuminance: A new paradigm

uniform and non-uniform LED luminaires. LR&T 2017; 49: 195-210.

for fashion retail stores. LR&T 2015; 47: 672-692. in lighting design. LR&T 2016; 48: 44-54. benefits of improved illuminance uniformity in parking lot illumination.

50. Yang Y, Luo MR, Ma SN. Assessing glare part 1: Comparing

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LR&T 50th volume

‘Some of the topics have been studied for many decades, others have disappeared and then returned, others that once were dominant are now absent, and yet others are emerging’ t

hoped they will at least learn something from the experience.

To be successful, the authors’ work has to be recommended by the anonymous referees. Referees are the unsung heroes of scientific publishing. They give their time and expertise without reward yet the quality of the reviews of submitted papers is what largely determines the quality of a journal. A good review will offer constructive criticism of a paper, spelling out where it is open to question, where it is at fault and how it might be improved. Without good referees, a journal is doomed. It is therefore a pleasure to thank the many, many people who have voluntarily refereed papers for LR&T over the years. Its success owes much to their efforts. It is also necessary to recognise the work of the publishers. Without their expertise, it would not be possible to produce and distribute such a professional product.

The future

In 2001 Peter Tregenza wrote that the central aim of LR&T was ‘to publish primary papers in lighting research’ but that it was also desirable ‘to provide a context in which new research can be appraised and understood by the non-specialist’. There is little doubt that the former aim has been achieved but the latter has not. Research today is ever more specialist, so much so that it has become impossible for even the most assiduous reader of the literature to keep up to date with all aspects of a multi-faceted subject such as lighting.

To overcome this problem, LRT Digests have been introduced. The concept behind these is that when a subject has matured sufficiently to produce a clear consensus on its implications for lighting practice, a document should be written

explaining the subject and its implications in language suitable for the non-specialist. So far, two LRT Digests have been produced, one on daylight guidance systems and another on maintaining brightness while saving energy in residential roads.

Both are available free on the LR&T website. More LRT Digests will be produced in the future.

Another objective for the future is to reintroduce the discussions of papers that were a feature of LR&T for many years. These discussions often arose from the questions and comments that were given following presentations at the IES sessional meetings in London. Just as sessional meetings have declined so have published discussions of papers. In many ways this is a pity, because the discussions often told the reader more about the meaning and limitations of the paper than the paper itself. Invited discussions of particularly significant papers are still occasionally produced but, in recent years, their frequency has been limited.

This is because the main problem facing LR&T today is the delay between a paper first appearing in Online First and appearing in print. Whether or not you think reducing the delay between electronic publication and print publication is necessary depends on your view of the future of publishing in print. There is no denying that electronic publishing has many advantages. It provides flexibility in arranging papers into issues that can vary rapidly in size and subject. It makes the use of colour in figures and images easy. It dramatically shortens the time between acceptance and publication. Yet many people feel that having a paper copy of a journal to hold and peruse is very satisfying. There are also some academic institutions that do not recognise a paper as published until it appears in print.

How long this dual electronic and print arrangement will persist is not clear. The production of journals has already become almost entirely electronic so by all logic printed journals should soon cease to exist and then the problem of the delay between publishing online and in print goes away.

Apart from this problem, LR&T is flourishing. For that to continue there are a number of essential requirements:

Maintaining a supply of interesting and useful submitted papers Having access to knowledgeable, willing and careful referees Ensuring the regular and timely publication of good-quality papers Providing a peer-review process that is fair and helpful to authors Creating an attractive product Having a communication system that is responsive to authors Having a website that provides easy access to the journal, either in whole or in part

Having a marketing strategy to increase awareness of the journal It is the aim of the LR&T editorial board to meet these requirements so that LRT can continue as the world’s premier lighting journal for many years to come.

Discomfort glare, daylight calculation and delivery, and more recently, the circadian system and LEDs are all persistent topics

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LR&T is published by Sage Publications (http://journals. sagepub.com/home/lrt). Vol 50, Edition 1 will be published on 8 January. Marking the 50th volume, and the inaugural International Day of Light, there will be a special LR&T symposium in London on 16 May 2018

Young Lighter of the Year

Cutting edge-lighting Young Lighter of the Year 2017 Matt Hanbury outlines his solution to the quest for an ultra-thin surface light source

its key limitations – improving the lighting performance and reducing the unit cost.

In order to bring this technology to market I was presented with a new challenge. I had to found a company, Lightly Technologies, and so I moved from mechanical engineer to entrepreneur, and embraced all the new challenges that came with it. I brought in ex-Philips Lighting industry veteran Brian Charman as a co-founder and together we set about enabling a new generation of luminaire and lighting design.

Approach to ultra-thin surface light sources The fundamental approach to developing our ultra-thin, surface LED light source module is in re-engineering the latest LCD displays technology to create a product for the lighting industry. However, this posed several major challenges for the engineering design.

We set our technical specification very high: to exceed current OLED technology in every metric, including light output, efficacy, lifetime, beam control, uniformity, colour stability, thermal management, bezel width, thickness and module robustness, while ensuring wide compatibility with existing LED drivers and controls to ensure Dali dimming. We have achieved all of these specifications and are now at engineering design freeze and preparing final tooling for mass production. @sll100

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Some years ago, OLED lighting emerged as an exciting new development in modern light source technology. It was immediately recognised by the lighting industry for the unique, ultra-thin luminaire designs that it enabled in decorative, retail and hospitality lighting applications. OLED lighting was well received but was held back by the high unit cost and poor lighting performance. Luminaire designers waited patiently for these limitations to be solved.

Fast-forward to 2018 and despite an industry-wide investment of $500m, OLED lighting is still not commercially viable. In fact the delta in cost and performance has only grown as LED technology continues to develop at a remarkable pace.

In early 2016 I embarked on a mission to solve these limitations of OLED lighting. Fundamental to this was understanding that a paradigm shift was necessary – the market wanted an ultra-thin, surface light source, not a lighting module using OLED technology. By taking a step back and applying some out-of-the-box thinking I came up with the solution.

Combining my experience working as a mechanical engineer at the Philips OLED factory in Germany and for Apple Inc on the LCD displays for the iPhone 6S in Japan, I invented a solution that uses LED technology to create a light module that has the appearance and form of OLED lighting, while solving

Young Lighter of the Year

in a single luminaire, designers can ensure functional lux levels on the working plane. We see the majority of our customers, luminaire manufacturers, using our modules to design modern suspended, task and surface-mounted luminaires, making best use of the ultra-thin profile. There are also significant opportunities for our technology in the automotive and aerospace sectors for interior lighting.

Vital statistics of the Hikari SQ light source shortly to be launched by Lightly Technologies

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Our patent-pending technology is essentially an advanced, miniaturised form of edge-lighting technology. It uses a light guide plate and a unique recipe of optical films to maximise light output and uniformity, as well as controlling the beam angle. In comparison to LCD display components, where the light output is under 100lm at 8000K CCT, we had to achieve a functional level of light of 300lm at the standard colour temperatures of 2700K, 3000K and 4000K, while also ensuring a CRI of more than 90.

While the majority of the applications of our technology will be in the decorative-focused lighting market segments of retail, hospitality and high-end office, the most fundamental specification was to achieve 300lm to create a truly functional level of light while minimising glare. By using several modules

Limitations of OLED technology The advanced design and manufacture of OLED lighting technology is truly a feat of modern engineering. Unfortunately these complexities are ultimately the reason behind the stagnation of OLED development.

As the name organic light-emitting diode implies, the fundamental physics behind the creation of photons of visible light is through a diode structure, in a similar way to a conventional LED. The material difference of the diode junction between OLEDs and LEDs is that while LEDs use silicon-based inorganic crystal substrates, OLEDs use organic (complex hydrocarbon) molecules that have electroluminescent properties.

The other major difference to LEDs is the design architecture of OLEDs. For OLED modules, the substrate is typically glass coated with a layer of the transparent, electrically conductive material indium tin oxide (ITO) which acts as the anode. This is followed by a number of layers of the electroluminescent OLED compounds as well as carrier layers for free electrons and electron holes. The cathode is an aluminium layer which also serves as a reflective back film to maximise light extraction from the module. These layers are then encapsulated by a thin-film plastic layer and finally a protective housing is typically added for improved robustness and thermal management, giving a final module thickness of around 3mm.

From my personal experience in working on OLED lighting, I have identified the three main reasons that have prevented the decrease in cost of the modules as cost of manufacture, material cost and yield loss.

The main challenge in manufacturing OLED modules is the precise nanometre scale application of the active layers.

Essentially, the difficulty of applying a uniform layer of material of nanometre-scale thickness, over an area at the 100mm scale. This is equivalent to painting a uniform 1mm layer of paint over a wall 1km square. This difference of six orders of magnitude needs to be done for each of the eight active layers.

The manufacturing process involves a technique called ‘vapour deposition’ where the individual OLED molecules are essentially sprayed on to the substrate. This has to be done

‘The advanced design and manufacture of OLED lighting is truly a feat of engineering.

Unfortunately, these complexities are the reason behind the stagnation of OLED development’ 10

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Young Lighter of the Year

‘Applying a uniform layer of material of nanometre-scale thickness over an area at the 100mm scale is equivalent to painting a uniform 1mm layer of paint over a wall 1km square’ in vacuum conditions to prevent oxidisation or contamination, within a different chamber for each material and with a curing step in between each layer. As a result, the cost of an OLED module production line is £20m-£50m.

The materials used in production are expensive, from the high-grade optical glass substrate, the purity of the electrodes to the high cost of the newly developed OLED electroluminescent compounds.

The final factor in the high unit cost is due to the low yield of the manufacturing process. Even with advanced manufacturing equipment there is a high proportion of OLED units produced that fail the quality control testing. There are many causes of this including black spots (due to oxidisation and contamination), uniformity issues and colour consistency.

The costs of these discarded OLED modules are borne by the final cost to the customer of useable units.

Technology development is most often funded by reinvesting revenue from existing sales; with OLEDs never gaining commercial traction the investment has had to come from the parent company. The lack of progress has since caused several high-profile manufacturers such as Philips and Osram to divest their OLED business units and so further stall the development of the technology.

Conclusion OLED technology has emerged as the future of the displays industry, increasingly used for smartphones and TVs. Conversely, OLED lighting does not look set to ever catch up with LED in either performance or price point. With this in mind, finding a commercially viable solution to the exciting ultra-thin, surface light source applications that OLED lighting pioneered is still important to luminaire and lighting designers.

Two years after starting the company, we have progressed through proof-of-concept and engineering development, and will be releasing early developer kits (four modules plus a driver) in February 2018 to enable our customers to start developing concept luminaries using our technology. We will launch the finalised product in the second quarter of 2018.

This feature is based on the original winning paper, Ultra-Thin Surface Light Sources: Picking Up Where OLED Stalled, presented by Matt Hanbury at the Young Lighter of the Year final. It took place at LuxLive, London ExCel, on 16 November Above: prototype versions of the ultra-thin LED light source and, opposite left, the final version of the Hikari SQ

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Interview

All-round brilliance

Designer Ron Arad crosses creative boundaries, but light is always an ingredient. Chris Fordham and Linda Salamoun talked to him at his London studio

You are unlikely to get simple answers from a character like Ron Arad. There’s always a twist in the way that he looks at the world and his projects. Arad is a contemporary designer famous for working with new materials and techniques over the past three decades, and who crosses the boundaries of architecture, design and art. Our aim was to discover more about his approach to light, how this was reflected in his work and especially in his more recent installations, such as Curtain Call at London’s Roundhouse towards the end of 2016.

The first thing Arad says is that inspiration is in everything around him, from the changing of a traffic light to a flood (which he mentions as the water drips into the room from the torrential downpour outside). The idea for Curtain Call came from the result of a casual chat he had with Roundhouse director Marcus Davey over lunch. Davey asked Arad if he would like to contribute to the annual art event held at the arts and concert venue every August. His response was immediate: “‘I said, let’s

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make something big and round… and also create something that is 360 degrees with seamless images that allows the audience to walk through them”. I was joking and had no idea how I would achieve it.’

Curtain Call has synergies with other works produced by Arad, and it is intriguing to see how, even if indirectly, they have influenced this piece. There is his Delight in Dedark exhibition (Galleria Marconi, Milan 2001), featuring works such as Inverted Pinhole Camera Obscura and Ballpark; his Two Floors exhibition (Galleria Marconi, Milan 2002), and the Swarovski Lolita pendant (Milan design week 2004). What is striking is how the products require a canvas to fully appreciate their function, and how the progression to this lighting installation has developed almost organically. ‘Walk in, penetrate, cross the moving images to get inside the cylinder,’ notes Arad. ‘You’ll be engulfed by images – a captive, but also a creator. It’s amazing what exciting things happen on both sides of the curtain.’

Asa Bruno

Hufton + Crowe

Asa Bruno

Interview

The greatest challenge, says Arad, was the fact that he didn’t know if it could be done. The final installation used 5600 8m silicon rods, but the original idea was to use a string of individual LEDs or some form of LED tape, which eventually proved too technically difficult for what he was trying to achieve.

What really made the project exceptional was its unpredictability, he says. Just 24 hours before it was installed it wasn’t clear if the installation was going to work in terms of the experience as it wasn’t something that had been rehearsed.

‘It is always good if the project is better than you feel you deserve... it was a lucky thing,’ he says self-deprecatingly.

The Roundhouse, being circular, was the ideal location for a circular installation, but the technology has been subsequently transferred to an exterior location under the name of 720 Degrees. So far it has been shown in two separate locations, the Isamu Noguchi garden of the Israel Museum in Jerusalem, and in Singapore as part of its International Festival Of Light.

‘You’ll be engulfed by images – a captive, but also a creator.

It’s amazing what exciting things happen on both sides of the curtain’

If all goes according to plan, the next installation will appear in Manchester some time in 2018.

Jerusalem allowed for a completely different experience.

During the day the installation took on a different form with the daylight coming through and creating its own effect, while at night the blanket of the curtain contrasted with the infinity of the sky above. In Singapore the installation took on a different guise again as it was used as much as a stage for performance as a work in its own right.

Arad says that he doesn’t have a particular approach or manifesto in regard to the way that he applies light to a project.

His ideas are very much driven by pure inspirations and items that he finds interesting to explore. Technology to him is a raw material like wood, metal and software, which can be moulded and used to bring his inspiration to life. If necessary, he doesn’t hesitate to employ other specialists to make his inspirations a reality. He doesn’t have an in-house team to provide the range @sll100

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Call the Shots Photography

Left: 720 Degrees in Singapore was a later manifestation of the original Curtain Call at London’s Roundhouse in 2016

Interview

He views everything visible as a stimulus for his creativity.

The way that manifests itself as products, installations, sculptures and architectural projects differs completely. The impetus behind each new project is unique t

of expertise he needs but there are certainly familiar faces to whom he repeatedly returns for collaboration.

Having said that, sister company Ron Arad Architects selfevidently takes lighting more into consideration in the buildings it creates. As an instance, director Asa Bruno outlined the challenges they faced with daylighting to the gallery spaces of the Design Museum in Holon, Israel (2010). In this case RAA challenged the client on the need for the more customary black box model, instead finding a balance between daylight penetration and control.

RAA researched the different daylight control options and identified a small, specific area for complete blackout, enabling the rest of the spaces to be sufficiently daylight controlled, using a simple Controlite system. This gave the ability to cut out around 90 per cent of daylight when required, allowing for gallery conservation requirements and display lighting. The approach, while partly selected based on budget constraints, ultimately enabled a very effective minimalist design.

For projects such as the Tel Aviv Opera House, Arad went directly to his old friend Ingo Maurer, for whom he has great respect, to help him design the lighting for the spaces. As with other areas of design, he pragmatically approaches people of various disciplines to make his concepts a reality.

Spending time with Ron Arad in his studio, it’s clear that he is driven, triggered by everything around him, and views everything visible as a stimulus for his creativity. The way that manifests itself as products, installations, sculptures and architectural projects differs completely. The impetus behind each new project is unique. Even if Arad doesn’t claim to work specifically with light or with a particular approach to light, it is present in his projects. Whether it’s being used as a digital medium, simply as a light source or by the way that light reflects and deflects through the chosen materials of his designs, it’s visibly, tangibly there.

Chris Fordham is senior lighting designer with Philips Lighting. Linda Salamoun is senior lighting designer with Steensen Varming Above right: the carefully calculated use of daylight at the Design Museum in Holon, Israel, creates minimal, highly effective spaces Centre: the Swarovski Lolita pendant (2004) evokes the idea of a traditional chandelier but acts as a functioning ticker board by displaying tweets and texts in real time Bottom: Inverted Pinhole Camera Obscura (2001)

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LR&T essentials

Surgical precision

Colour temperature in medical applications is a strong motif in the latest LR&T papers, finds Iain Carlile We begin with specialised lighting for medical procedures.

Mundinger and Houser’s paper investigates the correlated colour temperature (CCT) preferred by surgeons for surgical lighting. A prototype surgical luminaire, which proportionally blended warm-white and cool-white LEDs, was used to create four different experimental spectra: 3000K, 4000K, 4500K and 5100K, under which 16 surgeons evaluated the colour appearance of the internal anatomy of a large, midline incision in a 90kg pig. All four spectra were rated highly effective, although the 3000K option was rated less effective than the other three.

The authors noted that the surgeons appeared to have differing opinions as to which was the most effective spectra.

While the experiment involved only a small sample, the authors remark that the results of the investigation support the concept of task-optimised spectra for colour discrimination for particular tissue or conditions.

Shen et al’s paper also considers the illumination of biological tissue during surgical operations. The authors propose a method of controlling the illuminant spectral power distribution (SPD) of an LED to effectively enhance the visual contrast of tissue to aid discrimination. Five different (pig and chicken) tissue types were used in the experiment. They were viewed under optimised SPDs, which were compared to standard illuminants such as D65 and white LED light sources. From the results, the authors found that the samples viewed under the optimised illumination had a better visibility

perception, although this was achieved at the expense of the natural appearance of the tissue colours.

Also concerned with lighting in healthcare applications, Cui et al look at the emotional and visual effects on patients and staff in a cardiac intensive care unit (ICU). In a simulated hospital bed environment various different lighting scenarios were trialled, allowing colour temperature, lumen output and direction of the lighting to be varied, with both patients and nurses surveyed. From the results of the experiment, the authors found that all of the variables affected satisfaction of both patients and nurses, with patients preferring a warmer appearance of light and the nurses a cooler appearance.

Patient satisfaction is influenced by an emotional factor and a visual factor, of which there is an inverse relationship, and the visual factor is in positive correlation with the light level.

Liu et al’s paper investigates colour preference. Two psychophysical experiments were implemented with an empty light box. The authors found that the participants’ subjective ratings of the empty light boxes were similar to previous experiments that had had items on display in the light boxes.

The authors suggest therefore that this finding is either due to colour memory in the observers or due to the subconscious effect of human vision.

Iain Carlile, MSLL, is an associate of DPA Lighting

Lighting Research and Technology: OnlineFirst In advance of being published in the print version of Lighting Research and Technology (LR&T), all papers accepted for publishing are available online.

SLL members can gain access to these papers via the SLL website (www.sll.org.uk) Adjustable correlated colour temperature for surgical lighting JJ Mundinger and KW Houser Optimising the illumination spectrum for enhancing tissue visualisation J Shen, S Chang, H Wang and Z Zheng Lighting of a cardiac intensive care unit: Emotional and visual effects on patients and nurses Z Cui, L Hao and J Xu

Cross-section drawing of simulated ward (Lighting of a cardiac intensive care unit: Emotional and visual effects on patients and nurses, Z Cui et al)

Colour difference evaluation using display colours J Liang, M Georgoula, N Zou, G Cui and M Ronnier Luo

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EVENTS...EVENTS...EVENTS...EVENTS...EVENTS...EVENTS...EVENTS...EVENTS...EVENTS...EVENTS...EVENTS

2018 18 January Electrical know-how for architectural lighting designers (organised by the ILP) Venue: Conway Hall, London WC1 jess@theilp.org.uk

24 January Daylight in major projects (CIBSE Daylight Group) Speakers: Jurgen Koch, 4 Green Architecture; Laura Phillips, Buro Happold Venue: Institution of Structural Engineers London EC1 davidmcnair@btinternet.com

We the Curious, Bristol

23 January Non-visual responses to light (SLL and CIBSE Southern) Speaker: Prof Debra Skene Venue: Holiday Inn, Eastleigh, Hants sll@cibse.org

25 January, 22 February: SLL LightBytes in Birmingham and Bristol (pictured)

25 January SLL Lighting Knowledge Series: LightBytes Venue: Birmingham Botanical Gardens sll@cibse.org

22 February Lighting for Transport and Infrastructure Venue: Cavendish Conference Centre London W1 www.lightingfortransport andinfrastructure.com

2 February Lighting: legislation and energy efficiency (CIBSE training course) Venue: CIBSE, Balham High Road, SW12 www.cibse.org

12 March Junior Ready Steady Light (SLL event) Venue: Rose Bruford College, Sidcup sll@cibse.org

6 February Is lighting more psychology and art than science?

(SLL North East Region) Speaker: Henrik Clausen, director of Fagerhult Lighting Academy, Copenhagen Venue: Sandman Signature Hotel, Newcastle-upon-Tyne sll@cibse.org 6 February Technical seminar: DIALux evo lighting software (SLL and CIBSE North West) Speaker: Friedrich W Bremecker, head of sales DIAL Venue: Arup, Manchester 6-8 February Light School at the Surface Design Show (Exhibition and seminar programme organised by the ILP) Venue: Business Design Centre London N1 philippa.christer@montex.co.uk 22 February SLL Lighting Knowledge Series: LightBytes Venue: We the Curious, Bristol sll@cibse.org

Lighting Knowledge Series: LightBytes The Lighting Knowledge Series is kindly sponsored by Fagerhult, Trilux, Xicato and Zumtobel. For venues and booking details: www.sll.org.uk

13 March Ready Steady Light Venue: Rose Bruford College, Sidcup sll@cibse.org 18-23 March Light + Building Venue: Messe Frankfurt https://light-building.messefrankfurt.com 12-13 April CIBSE Technical Symposium: Stretching the Envelope Venue: London Southbank University www.cibse.org 26 April SLL Lighting Knowledge Series: LightBytes Venue: Life Meetings and Events, Newcastle-upon-Tyne sll@cibse.org 8-10 May Lightfair Exhibition and Conference Venue: McCormick Place, Chicago www.lightfair.com 16 May International Day of Light Including LR&T symposium www.lightday.org/www.sll.org.uk

LET Diploma: advanced qualification by distance learning. Details from www.lightingeducationtrust.org or email LET@cibse.org CIBSE Training: various courses across the whole spectrum of lighting and at sites across the UK. Full details at www.cibse. org/training-events/cibse-cpd-training LIA courses: details from Sarah Lavell, 01952 290905, or email training@thelia.org.uk For up-to-date information follow us on Twitter @sll100