Lighting Journal February 2018 by Matrix Print

Professional best practice from the Institution of Lighting Professionals

February 2018

HEART OF THE MATTER Smoke, lasers, illusion… and brilliant lighting DISRUPTED DESIGN Understanding the implications of the rush to connected lighting TRUE BLUE? Where do the ‘danger edges’ really lie for blue light, and blue light hazard?

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February 2018 Lighting Journal

Contents

06 OF THE 06 HEART MATTER

The final ILP ‘How to be brilliant…’ lecture of 2017 was a fascinating immersion into GNI Projects’ world of smoke and mirrors, lasers and illusion, as Graham Rollins and Ingo Kalecinski showed

DISRUPTED DESIGN

In the rush to connected lighting and digitisation, does the lighting industry really understand the implications of the change it is helping to drive? A high-level panel of lighting experts gathered at LuxLive in November to debate this future. Lighting Journal listened in

18 COLOUR CHANGE

The days when the CIE General Colour Rendering Index was sufficient to describe the colour rendering of a light source are coming to an end. Janine Stampfli looks at what will replace it

THAN MEETS 22 MORE THE EYE?

Where do the ‘danger edges’ lie for blue light and blue light hazard? Are LEDs really harmful to health? In his presentation to the ILP’s Lightscene CPD event, Alan Grant assessed the recent evidence

30 EXECUTIVE PERKS

A new executive lounge at Oslo’s Gardemoen Airport uses architectural tuneable LED lighting that can help passengers to work, relax or even, it is argued, beat jet lag

32 SOLAR SYSTEMS

For up to 600 million people in Africa, their only light source is the flickering, toxic and polluting flame of a kerosene lamp. The charity SolarAid is breaking this cycle by giving communities access to clean, renewable light, as Oliver Sylvester-Bradley explains

34 PATIENT EXPECTATION

Reducing energy and maintenance costs were important factors in a US healthcare company’s decision to switch to LED. But fewer slips and trips and a better environment for patients and staff alike were also high on the list

Professional best practice from the Institution of Lighting Professionals

Feb 2018

36 CAMPUS LEARNING 40 GAS POWER Lincoln College has reduced its energy and maintenance costs, become more environmentally friendly and created a more engaging learning environment, all by tapping into Salix Finance

38 TOMORROW’S WORLD?

The so-called ‘smartification’ of everyday life – automation, connectivity and security – will be a key focus for next month’s Light + Building international lighting fair in Frankfurt

Once the electric lamp arrived, it is easy to assume gas for lighting was quickly swept away by the march of this exciting new technology. In reality, however, gas lighting hung on quite tenaciously throughout the 1930s, explains Simon Cornwell

44 NEWS FROM THE ILP 46 LETTERS TO THE EDITOR 50 DIARY

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p COVER PICTURE

Broken Heart, one of GNI Projects’ multi-layered, light-led installations, and the subject of November’s ‘How to be brilliant…’ ILP lecture

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February 2018 Lighting Journal

Editor’s letter

Volume 83 No 2 February 2018 President Alan Jaques IEng FILP Chief Executive Richard G Frost BA (Cantab) DPA HonFIAM Editor Nic Paton BA (Hons) MA Email: nic@cormorantmedia.co.uk Editorial Board Tom Baynham MEng MA (Cantab) Emma Cogswell IALD Mark Cooper IEng MILP Kevin Dugdale BA (Hons) IEng MILP Graham Festenstein CEng MILP MSLL IALD Nathan French John Gorse BA (Hons) MSLL Alan Jaques IEng FILP Gill Packham BA (Hons) Nigel Parry IEng FILP Richard Webster Art Director Adriano Cattini BA (Hons) Email: adriano@matrixprint.com Advertising Manager Andy Etherton Email: andy@matrixprint.com Published by Matrix Print Consultants Ltd on behalf of Institution of Lighting Professionals Regent House, Regent Place, Rugby CV21 2PN Telephone: 01788 576492 E-mail: info@theilp.org.uk Website: www.theilp.org.uk Produced by

Matrix Print Consultants Ltd Unit C, Northfield Point, Cunliffe Drive, Kettering, Northants NN16 9QJ Tel: 01536 527297 Email: gary@matrixprint.com Website: www.matrixprint.com © ILP 2018 The views or statements expressed in these pages do not necessarily accord with those of The Institution of Lighting Professionals or the Lighting Journal’s editor. Photocopying of Lighting Journal items for private use is permitted, but not for commercial purposes or economic gain. Reprints of material published in these pages is available for a fee, on application to the editor.

appreciate it is perhaps impolitic within a journal devoted to lighting and illumination to admit that I breathe a sigh of relief when, in February, you begin to get the first glimpses of brighter mornings and evenings. Spring may still be some way off, but it finally feels as if the darkness of winter is (ever so slowly) beginning to recede. Nevertheless, as Graham Rollins and Ingo Kalecinski of GNI Projects highlight in this edition, the dark winter months nowadays give lighting professionals an important opportunity to showcase to the public just what modern light and lighting can do, how lighting technology is advancing apace, and how lighting can be so much more than just function. In their case, it is stunning light-led displays, most recently Heart Beat at Salford’s Lightwaves Festival, which has itself become a regular fixture in the Manchester winter calendar. Winter is very much now the season of light festivals, notably Lumiere Durham in November and last month’s Lumiere London, both of which we shall be reviewing in March’s Lighting Journal. Where once winter illuminations might be (at best) a few Christmas town lights, there are now myriad local light festivals up and down the country – Hull’s City of Culture light and robotics installation ‘Where Do We Go From Here?’, the various Magic Lantern festivals, Truro’s City of Lights, York and Longleat’s Christmas festivals and, of course, LewesLight in East Sussex, to name but a few. These not only provide an entertaining diversion to pierce the winter gloom, they help to educate the public about light as art and spectacle while at the same time celebrating the skill, passion and creativity of lighting professionals. Initiatives such as this year’s International Day of Light can serve much the same function in bringing the power and beauty – the possibility – of light and lighting to a much wider audience, not least younger generations who, in turn, may one day be inspired to become the lighting professionals of the future. For all these reasons I, for one, therefore very much hope the industry will support, promote and get firmly behind this year’s events on 16 May (and for more details check out https://www.lightday.org/), just as it did 2015’s International Year of Light. Nic Paton Editor

q SUBSCRIPTIONS

ILP members receive Lighting Journal every month as part of their membership. You can join the ILP online, through www.theilp.org.uk. Alternatively, to subscribe or order copies please email Diane Sterne at diane@theilp.org.uk. The ILP also provides a Lighting Journal subscription service to many libraries, universities, research establishments, non-governmental organisations, and local and national governments.

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February 2018 Lighting Journal

The ILP’s ‘How to be brilliant…’ lecture series

HEART OF THE MATTER

The final ILP ‘How to be brilliant…’ lecture of 2017 was a fascinating immersion into GNI Projects’ world of smoke, mirrors, lasers and illusion, not to mention electroluminescent wires and cable ties. This is an abridged version of their presentation By Graham Rollins and Ingo Kalecinski

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February 2018 Lighting Journal

e are both architectural lighting designers by day and have been working in the field for around 13 years each, but have been friends for quite a bit longer than that. Eight years ago, the opportunity came to us to participate on our first artistic project together, and that pretty much started GNI Projects. We have to balance our commitments carefully between the architectural lighting side and the light art side with GNI, so we are typically only involved in three to four projects a year and try to do one to two new pieces each year. We titled this lecture ‘How to brilliant with smoke and mirrors’ because we thought it was very appropriate. A lot of our pieces have, quite literally, used smoke and mirrors to direct light, to shape light, and to visualise light in a confined space. But, obviously, ‘smoke and mirrors’ is also a term associated with magic and magic tricks. When we do something new we always set out to create our own little piece of magic and illusion to engage the viewers as much as possible. What we’re going to show here is the thinking and mechanics behind a few of our key projects.

t LIGHT LOVES FRANKFURT

‘Light Loves Frankfurt’ was our first commission as GNI Projects, for the Luminale in 2010 in Frankfurt. Luminale is a fringe fair that runs alongside Light + Building and normally has around 100 installations. The basic premise was that, generally, so many people from the UK go to Frankfurt for the show, and we all have a certain amount of love for that city. We thought of the typical iconic ‘I♥NY’ logo, we thought ‘we love Frankfurt’, ‘we love light’. So, we tried to do something that was a bit of a play on those themes, which is where the original idea of using hearts in our work came from. The piece was constructed inside a corridor that went underneath the hotel, into a break-out space in the courtyard at the back. However, one of the things we realised pretty quickly was that smoke doesn’t deal very well in a corridor space! So the haze had to be quite focused. We had rented some fans and a haze machine, but we had to experiment on site with wind being pulled through the tun-

nel, so we had to put up a clear curtain. The basics of it is that it is a heart rendered out of crisscrossing laser beams, which represents the blood-red of the heart, the red lasers. The heart is bound into the space by these lasers that break out, which connect to the walls. There were 24 mirrors and 12 lasers. The mirrors were on small gimbals, which allowed us to rotate them in three-dimensions. Although the heart itself is a 2D plane, and it is a single plane with lasers, we were, after the second bounce of every laser, able to spring the line of light outside, which made it looked like it was tied to the walls with light itself. We were keen on people being able to interact with the piece. We had people coming up and putting their hands through it and experiencing it at close quarters. But, being our first project, it was also a bit of a learning curve for us. We had to experiment quite a lot with the space and the fan position. For example, we did not want the lasers to be there all the time; we wanted them to dance and play around a little bit. So, as the smoke moved through it, it pulsed, almost like a heart would. You could see it undulating and moving as people moved through the space and walked around it.

t LIGHT LOVE LIGHT

‘Light Love Light’ was our second piece, which again we conceived for a light festival in Germany. We used electroluminescent wire, which proved a bit tricky to handle, so we had to learn fast! Stylistically, this uses very much the same graphic language as the original laser heart, so red illuminated lines crossing one another and drawing the outline of a heart. But we, quite literally, added a third dimension by splitting the lines of light over ten layers and spreading those layers out. You can see a perfect heart from two perspectives, front and back. But as you move around the object, the lines of light would change their appearance. Whereas the interaction of our previous piece was to touch the light, this time visitors were encouraged to move around the object and find the perfect vantage point from which to see the heart. For us, we’ve never really been into digital interaction. We’ve always had these perspective games that we play, so people have to find that vantage point and interact with it, but on a more physical sense rather than, say, sending a text or controlling it with via other digital means. www.theilp.org.uk

February 2018 Lighting Journal

The ILP’s ‘How to be brilliant…’ lecture series

q BROKEN HEART

When we went back to the Luminale in 2012, at The Plamengarten in Frankfurt, we created this piece, entitled ‘Broken Heart’. As we went from 2D to 3D between our first two pieces, we this time tried to abstract that even further by using layers and with those layers then further broken into pieces. Rather than having your typical digital pixel of a point source, we decided we could make the pixels into lines. We were using linear pixels, which had the same language of the red lines of light, but it was a more digital thing. Because we are architectural lighting designers, with GNI we try to use things we don’t get to use in our day jobs – lasers are not something you get to use very often as an architectural lighting designer, or electroluminescent wire.

To that end, we avoided using LED for a while, but this was our first LED piece. The reason was that we knew we were going to be in an external environment where we did not have the ability to control the environment. We knew we couldn’t use haze and we had to have something that was bright enough to be seen at dusk, which led us to LED. This piece has a slightly more industrial aesthetic, more exposed jointing and cabling. It is much more 3D but also, because of the way the pixels work, was probably our most abstract piece. There was always a chance with the earlier pieces to see the single layer; whereas with this piece, when you moved off to the side, it became much more broken, which was the reason for the name. This was a really successful piece for us; there were 31,000 visitors. It was a really fantastic thing to know that a lot of people had seen it.

8 p ONE BEAM OF LIGHT

Our next project, ‘One Beam of Light’, was created for a photography exhibition of the same name at the Institute of Contemporary Art in London in 2013. We were asked to create a physical representation of the theme. What we came up with is this structure which has multiple, custom-made little mirror holders on arms inside. It looks like a single green laser line bouncing from all these points, creating this beautiful mass of zig-zagging glowing lines from pretty much every angle as you walk around it; so it is quite mesmerising and catchy. You see all these random lines as you move around and only from one point could you, more or less, clearly read the word ‘Light’, which was from where people would enter the actual exhibition. Technically, one of the important things with this project was that, while it had to look like a single beam of light, actually there are about 16 lasers in there. We couldn’t get that many bounces out of a single laser. Even though we used a very pure metallic mirror, a laser always diverges a little bit with every reflection. We’ve learnt over the years that, generally, you can bounce a laser about two www.theilp.org.uk

February 2018 Lighting Journal

p IMPLIED CANDELABRA

times before it starts to become too wide, too ethereal. So we concealed lasers within the heads, which matched the other heads. It appeared to be one line, one beam of light, but it was actually many lasers. The fact the lasers danced and changed with the smoke as people went through them was an important part for us. We al-

ways wanted it to be something that had some animation, some theatre. It is very easy to fill a room with smoke and so, actually, our issue here was limiting the smoke. So, we used things like PIRs and timers and sensors to make sure you only got a puff of smoke at the right time, so it didn’t over-densify the space.

‘Implied Candelabra’ was a project we did for a dance studio and theatre space called the Elephant Paname gallery in the heart of Paris. This was our first proper private commission in a gallery, produced with Light Collective, so that was the ground-breaking part for us; it was a great honour to be asked to do it. When we looked at the space we noticed there was an old chandelier hook, as it was quite an historic building. So, we decided to use that hook as our inspiration and build a ‘chandelier’ that would look like a candelabra. We, again, had a very small space to work within; it was actually the transition area from one piece of art through to another, so there was always this interaction, of doors opening and closing. We wanted to make sure, again, that we didn’t over-fill the space with smoke, so we had a sensor on the stairs. When people walked past, it would have a time delay of around about one or two seconds and then, as they opened the door, there would be a puff of smoke from above, which would make the chandelier appear. They would move through it to the next space as it disappeared. It was quite a complex piece. There were 40 lasers and 80 mirrors, and the chandelier itself was 1.3m high by 900mm wide. Each candle had seven mirrors to make the candlestick, and then on the tops of those we used suspended crystals. The crystal was added with a laser firing straight into it; and was held loosely, so that when people moved through the space, the breeze made them wobble, so they flickered and twinkled like candles. It was great because it was a fully-3D form. You were able to get all the way underneath and look up at the piece. That gave us a new dynamic, having people walk under the piece. It was nice to watch the way people experienced that in the space. www.theilp.org.uk

February 2018 Lighting Journal

The ILP’s ‘How to be brilliant…’ lecture series

p HEART BEAT

This was our biggest project to date. We were approached by a company called Quays Culture, which curates a show in the Salford Quays area – the Lightwaves Festival. Although initially we proposed other ideas, and we were trying to move away from hearts, the client ultimately wanted a heart! So, it was one of those things, ‘OK let’s do another heart, but let’s make sure it’s something fresh, something new’. We try to make sure that all of our pieces challenge us, and we don’t want to repeat ourwww.theilp.org.uk

selves. Every heart that we have done is always using new technology as well as a new set of imagery. From the side, when the heart is active, again it’s a mess of lines, an abstraction. Although we were on layers, we actually made those layers 3D, so the leading line or the line that made the heart was always on a flat plane. But then we had a dog-leg that came out and gave us the 3D. So, when you moved around it, it had much more 3D than just a lot of slices. There were two distinct modes. The first mode, which was a pulse light, was like an

ECG pulse through the middle. It was constantly pulsing, which attracted people from the side. The first view you had was from the car drop-off area, and you were looking at the side, at it pulsing. Then you had to walk round it to find out its true form. The second mode had all the elements lit. It was right in front of the Lowry Gallery, in an area that is really vibrant for dance, theatre, lighting and art exhibitions. You also have the Imperial War Museum North close by and the BBC Media City. It was quite a brutal install, although a lot of fun; it was December in Salford, so it

February 2018 Lighting Journal

developed the cable tie is our hero! It was conceived so that somebody could put up the scaffolding without us being there, and then we’d come along and put in the final elements. Everything we didn’t want people to see, we ensured was painted matt black. So the red light was very saturated. The idea was to try and lose the framework or the cabling as much as possible by painting it out black. The festival also prides itself on being interactive, and so were asked if we could add a certain level of interaction. Again, we didn’t want a mobile phone application or anything like that. So we made our own control system and added two touch-pads. Each person held one pad either side, and the interaction that would trigger the central heart would be either to hold each other’s hand or to kiss each other! Basically, it needed two people to connect the circuitry, to expose the heart in the centre. Then the heart would come on, the pulse keeps running, and then after five seconds slowly fades back. The line the pulse took wasn’t a straight line, it actually bisected the two halves of the heart; the left-hand side and righthand side were split by the pulse. On the framework we had 16 spotlights that were activated by the touch pads, and they were angled eight on each half of the heart. Then the lights that ran through the middle, they were on an automatic control. It was important for us that people weren’t able to do the touch-pads on their own. We purposely put the pads just a little bit too far apart so you couldn’t actually do it on your own; you had to go with a partner or make a new connection with somebody else. So, the security lady that was standing there, she had to hold a lot of people’s hands! We had little children activating it. We at one point even had six of them in a row, seeing how many people they could get in before

was cold, there was a lot rain and also a lot of wind! We had to be really careful about the technology, as it was quite delicate. All the luminaires were pre-made with lengths of cabling on them. We wired them all back into the control hub, which was in the front of the sculpture. And they remain in that form; there is never a scenario where they get broken away. When we take this piece down, all of those get coiled up, put on top of the box and put into a storage unit. All of the parts or elements are tied on to the tension wires with cable ties. The cables, too, are tied on with cable ties. Whoever

it wouldn’t work anymore. It was fantastic. It was probably the first time we had used interaction in this way, and it was probably the most special part of the piece, really; that people really did feel a bond to our piece of art by bonding with each other. We had a queue of people even in the rain, which was quite nice, and some people going round a couple of times. The original plan or brief was to provide a package for the client to be able to set up the installation again without us. Some elements of this worked, such as the frame and tension wires, but it was also apparent to us that the sculptural piece was too complex to be fully set up without our input. For future shows we have always attended and install the final artistic elements ourselves. It is one of those things as designers, as professionals. We get asked quite often, ‘what makes that art and makes what you do for your day job design?’. One of the ways we’ve always thought about it is that a design can be given to somebody in a set of drawings and somebody else can reproduce that. The thing with this is there is always a certain amount of artistry in there. Although we do have drawings to support it all, it became very apparent to us that there was no way anyone else could have built the piece on site exactly as we intended from drawings. Even we never install anything exactly the same way twice, a bit like a singer never sings a song exactly the same way twice. When we tweak each piece it doesn’t always go together exactly as per the drawing. There is always a little bit of artistry in there. For me, that is what defines art. You need the artist there to recreate it; you can’t just do it purely from drawings.

Graham Rollins and Ingo Kalecinski are directors at GNI Projects

THE ILP’S 2018 ‘HOW TO BE BRILLIANT…’ LECTURES This year’s programme of ‘How to be brilliant…’ lectures is due to kick off from March and run throughout 2018. At the time of writing, in January, not all speaker slots had been confirmed but the key dates to get in your diary so far are as follows:

14 March (Christopher Knowlton from 18 Degrees) 25 April (Sally Storey from Lighting Design International) 23 May (Lisa Hammond from Gravity Design Associates) 19 September 17 October 28 November

Do be aware, there will be a change of venue this year. The lectures will be held at Body & Soul, Rosebery Avenue, London EC1R 4RE. Keep an eye out online for updates and confirmation of speakers, at www. theilp.org.uk/brilliant and more details will be revealed within Lighting Journal as they become available.

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February 2018 Lighting Journal

Lighting and the digital revolution

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February 2018 Lighting Journal

In the rush to connected lighting and digitisation, does the lighting industry really understand the power and implications of the change it is helping to drive? A high-level panel of experts gathered at LuxLive in November to debate how this future might look. Lighting Journal listened in By Nic Paton

he ‘Internet of Things’, connectivity and data were key themes and discussion points at LuxLive in November; indeed, there was a whole new ‘Smart Spaces’ area devoted to all-things connected. But in all the excitement and rush of this unfolding digital revolution within lighting, is there a risk for lighting professionals? Is there a danger that the scope for creativity and beauty in lighting design becomes diluted, even lost altogether? What will be, or need to be, the role of independent lighting designers within this evolving landscape? Under the broad question of ‘Disrupted design – will quality suffer in the rush to connected lighting?’, LuxLive brought together a high-level panel of lighting experts to debate these issues, and more. The panel comprised Colin Ball, lighting director at BDP, Paul Beale, director at 18 Degrees and Electrolight, Jeff Shaw, associate director at Arup, and Joe Vose, associate designer at Light Bureau. The discussion was led and chaired by John Bullock, applications editor of Lux Review. John opened the proceedings by introducing the panel and setting the scene. ‘Conversations I’m having from the design end of things is that we need to get a grip on what we’re doing, on whatever this thing is [digitisation and disruption], because if we don’t, it will roll over us. ‘Our world will not carry on without change, we’ll suddenly find that the briefs are very, very different, and we’re having to use connected light fittings the like of which we wouldn’t give house-room to. So how do we get to where we want to be?’ he asked. ‘My biggest concern is that, as lighting designers, we’re pushing against many assumptions of what people think lighting www.theilp.org.uk

February 2018 Lighting Journal

Lighting and the digital revolution

is about,’ argued Colin Ball. ‘Lighting is not a grid of down-lights, and one of our biggest concerns is we have new people entering the industry who know nothing about light. But they’ve got billions to invest, which they’re pouring into the industry for their own ends, for data monitoring and for data collection, which is the important part. They’re assuming that all lighting is a grid in the ceiling. And for us, fundamentally, it is not.’ ‘We have to remember that the primary thing we are trying to do is light the space for people,’ agreed Jeff Shaw. ‘Mobile phones, smartphones – now almost the last thing you use them for is to make a phone call. That’s not to say the other things aren’t useful, but you wouldn’t want a smartphone that lost that function. We need to consider, it’s not just a grid of downlights; we have to design the space to accommodate whatever the conwww.theilp.org.uk

nected, smart lighting is supposed to do; that that does disrupt what we do. ‘At the same there’s a lot we can embrace from it, there’s a lot that we still don’t know what we can do, especially around the data collection. I want lighting to know when it should be on and when it should be off on its own, but without necessarily having to interact with it and take a grip of our lives. We’re not there yet, but we need to make sure we keep control of it,’ he added. One of the issues, and uncertainties, around connected lighting at the moment was that there is not, as yet, one dominant platform, argued Joe Vose. ‘Anyone remember HD DVDs, Betamax? Clients are afraid to invest in case they end up with an HD DVD not Blu Ray. So, we need a stable platform to start building these projects on, or else it’s going to be the wrong time to start doing this.’ Paul Beale highlighted how he had just

come from a presentation by Mark Sutton Vane that had echoed the keynote talk he gave to last year’s ILP Professional Lighting Summit on the beauties of hidden light and telling a story through light (Lighting Journal, September 2017, vol 82, no 8). ‘If we’d said to him, “well you can’t put the lights in a concealed place because we won’t get the signal correct for the Internet of Things that we need to have” then I think we’re going to be in a worse place than we are at the moment. There is this constant push for more efficient lighting; the regulations are trying to squeeze more and more lumens out of every watt of light, that’s what we’ve been told we will need to do as an industry. ‘Yet on the other side of the industry it’s “we need these lights, and we need them everywhere in this format and they need to be on standby mode all the time” and that really concerns me. Because we’re

February 2018 Lighting Journal

talking about thousands of lights that on all the time, this trickle of current even when they’re off, because they’ve got this secondary function for Li Fi and IoT,’ he added. There were also important questions to be debated around the potentially diminishing role, and influence, of the lighting designer in this evolving world, argued Colin Ball. ‘From day one, before they’ve even appointed the lighting designer, they’re saying “can we have it connected, can we have the light fittings monitor building occupation, can the light fittings, when someone arrives, tell them what building to go to?”. ‘We’ve now got three clients asking us about this. Always the assumption is they’re speaking about a grid of downlights in their ceiling. And we’re saying, “hold on, our system won’t even give you a ceiling, can we talk about the 70% energy saving we could give you by orientating the

building correctly?”. And that’s something that concerns me.’ ‘The revenue of the future is the data that all of this is going to create,’ conceded Jeff Shaw. ‘That’s the same way that Google makes it money. It’s about the data. Whether you think that’s sinister or not is up to you. I have an Android phone, so I know I’m giving Google information on almost everything in my life. But in return it gives me lots of free stuff.’ ‘There is talk of companies giving away light fittings for free to get the data,’ agreed Joe Vose. ‘I’ve spoken to companies where they’ve been offered free lighting so that the data could be harvested from them, eventually. It’s very much a Silicon Valley thing, get a lot of people together to develop a service, and then work out how you can make money from it. ‘Ten years’ ago no one from Facebook knew how they were going to make money

out of it, and it turned out it was the advertising. And I think we may be seeing the beginnings of the same thing in lighting now. We don’t know how we’re going to make money out of connected lighting, but let’s get 10,000, 100,000, a million households connected, and then we can work out what we can sell to them,’ he added. ‘It would certainly disrupt my design if the alternative was free to what I was proposing,’ laughed Jeff Shaw. ‘So, as we drift aimlessly down the road to authoritarian fascism, should we do that with a good, well-lit environment?’ questioned John Bullock, tongue firmly in cheek. ‘Why not?!’ agreed Jeff, to more laughter. ‘I was recently in Berlin and if you go around the streets of Berlin, it’s dark,’ highlighted Paul Beale, more seriously. ‘And it’s beautiful. There is the odd thing that is lit but, because you’ve got that hierarchy of light, it’s just inherently interesting. ‘Yet, what we see over here is increasingly overlit spaces; again, driven by people who stand to profit from lots of lighting equipment. We need to be aware of this and keep our eyes open. I think the first priority has to be well-lit, beautifully lit environments. If there’s some data-mining, data collecting advantage that can sometimes be integrated into the light fittings, then we’re probably not in a position to be able to stop that. But I think poetry and beauty has to come first.’ ‘The next step we are going to see is all of these sensors: for presence, for heat, for infra-red, for phones and so on, they’re getting smaller and smaller, to the point that they are going to be within every single LED chip,’ argued Colin Ball. ‘What we’ve got at the moment in the industry is this Wild West with everyone trying to sell an embedded network. But the other historic thing of the lighting industry is that it is the inventor of inbuilt obsolescence. The lighting industry is very good at leading the way, but it doesn’t quite understand that putting all this data and intelligence together in the fittings, that’s probably not the future? ‘The future is, like it or not, the microphones and data monitoring – devices such as Amazon’s Alexa – that we’re buying each other. At the moment, they’re an optional choice. But in the next five years they won’t be. Every device you buy will have these sensors in them already: your fridge, your kettle, your lamps, and they will all be talking to each other. One technology will stabilise and, before we know where we are, this data collection will be everywhere – and it won’t be anything to do with the www.theilp.org.uk

February 2018 Lighting Journal

Lighting and the digital revolution

lighting industry,’ emphasised Colin. ‘It’ll be “we’re making life better for you” but at the same time it’ll be we’re learning more about where you are and what you’re doing. Just walking into the office – people will know if you’re not there,’ agreed Jeff Shaw. ‘I can see this horrendous possibility coming at us,’ suggested John Bullock. ‘At moment we’re being complicit in it because we’ve got the carrier for it. We are choosing to be complicit. So, do we go “yeah that’s OK because what somebody does with the data is up to them”? Or do we turn round and say “it is nothing to do with us, if you want to collect your data go and do it somewhere else”?’ ‘Fundamentally, the people in the building are still the most important resource, and we have to make sure we prioritise that, prioritise lighting for people,’ argued Jeff Shaw. ‘That should be the start with every design we do. Yes, we’re complicit at the moment in thinking, “well what can we do with this style of lighting, how can it improve the experience of people in these buildings, how can it better control things?”. But yes, it is a fine line.’ www.theilp.org.uk

‘There are a lot of people who are controlling that data who do not really know that lighting design is even a job. So, we’re not really high influencers, and that is a tricky part,’ argued Joe Vose. ‘There is nothing we can do about this. It is coming. It is like the tide coming in. It doesn’t matter whether we have some moral objections or whatever. This is coming and if we dig our heels in and say, “not on my patch”, they’ll just get someone else to do it. That’s the issue,’ worried Paul Beale. John Bullock then wrapped up the discussion with a personal, but illuminating anecdote. ‘Back in the Thatcher days, those of us who are old enough to remember those dark days, I was a bit active politically – not on her side. ‘I was at home one day and there was a knock on the door. It was guy from BT, and he said, “you’ve reported a fault on your phone”. My wife wasn’t in at the time and so I assumed it was something she had done and said “Ok, come in and do what you have to do”. Once he’d left, I picked up the phone and you wait to hear the click at the other end. I’m not necessarily convinced we had been bugged, but that was what the security

forces were doing at the time. ‘We had a good friend who was working for Michael Heseltine at the time, at the environment ministry. I rang him and said, “I think we’ve just been bugged”. He said, “yeah probably. But, don’t worry, you’re not important enough to listen to”. So on that note, amongst the seven billion of us, the chances are that most of us won’t be important enough to listen to.’

THE PANEL Colin Ball, lighting director, BDP Paul Beale, director 18 Degrees and Electrolight John Bullock (chair), Lux Review Jeff Shaw, associate director, Arup Joe Vose, associate designer, Light Bureau

February 2018 Lighting Journal

Colour rendering metrics

COLOUR CHANGE 18

The days when the CIE General Colour Rendering Index was sufficient to describe the colour rendering of a light source are coming to an end. Many new colour metrics have been proposed, and two have recently been endorsed by lighting authorities By Janine Stampfli

and colour rendering. The former is quantified by the temperature of the blackbody radiator whose colour most nearly matches the colour of the light source, that is its Correlated Colour Temperature (CCT), but is often described with non-technical words such as ‘warm’, ‘neutral’ and ‘cold’. For colour rendering, the standard tool in use for the last 50 years has been the General Colour Rendering Index (CRI, also called ‘Ra’).

DEVELOPMENT OF THE GENERAL CRI

As most lighting professionals will undoubtedly know, the General CRI was first published by the Commission Internationale de l’Eclairage (CIE) in 1965, as fluorescent light sources became more and more popular. They had very different

spectra than incandescent light sources and therefore revealed surfaces with the same spectral reflectance differently. The General CRI provided a means to distinguish between them. In simple terms, the General CRI calculates the average extent to which eight test colour samples illuminated by a test light source have their colour appearance changed compared to how they appear under a reference light source at the same CCT. When there is no difference, the General CRI is given a value of 100. As the difference increases, the General CRI decreases. Lighting codes and standards usually specify minimum General CRI values for different applications. In 1974 the CIE published an updated version. Besides some mathematical

olour and light is a highly complex topic, and one can spend a lifetime studying it. Colour is essentially a perception and depends on the interplay of three components: a light source’s emission spectrum, an object’s spectral reflectance, and our visual system. Whereas we have means to objectively describe the first two, the last component moves the topic into more complex territory. Traditionally, the colour properties of a white light source are described in terms of two components: colour appearance www.theilp.org.uk

Figure 1. CRI test colour samples one to eight (top row) and nine to 14 (bottom row) [1]

February 2018 Lighting Journal

p p

Figure 2. TM-30’s 99 test colour samples [5]

changes, six test colour samples (two representing white skin tone and vegetation and four high chroma samples) were added as a response to criticism that the original eight test colour samples were all pastel shades, as shown in figure 1. The CIE’s new recommendation was to calculate the special CRIs for each of the now 14 test colour samples in addition to calculating the average of the first eight for the General CRI. However, over time further deficiencies were found. The still relatively small number of test colour samples was said to leave scope for spectral engineering, in other words the selective optimisation of colour properties of light sources during the development stage. Also, with the development of newer, more accurate colour spaces, the colour space used in the calculation of the General CRI became outdated as did its chromatic adaptation transform. Further, the discontinuity in the spectrum of the reference source from a blackbody radiator for CCTs of 4999K and below to a form of daylight at a CCT of 5000K and above was considered incoherent. In addition to such deficiencies, the General CRI was also criticised for having some inherent limitations. Because of it being an average, light sources with the same General CRI value (at the same CCT) may still render colours differently. Also, the General CRI is a relative measure, as its score is linked to a certain CCT. General CRIs for light sources with different CCTs should not be compared. Unfortunately, the General CRI is now often used as a measure of overall colour

Figure 3. Test and reference light source gamut area polygons depicted with the 16 hue bins [5]

quality, which is something it was not designed to be. It was developed to characterise how ‘true’ or ‘natural’ objects were rendered by electric light sources. In today’s terminology we would call it a ‘fidelity metric’. It is adequate to separate light sources that are widely different. And being a single number, it has the advantage that it is simple to understand.

Then, after 40 years of disagreement, one proposal did get a lighting authority’s ‘blessing’. However, it was not the CIE but the Illuminating Engineering Society of North America (IESNA) which published a new method to evaluate light source colour rendition called ‘IES TM-30-15’ (‘TM-30’ in brief ) in 2015 [4].

ALTERNATIVE APPROACHES DEVELOPED

TM-30 not only offers a potentially better version of the General CRI, it offers a comprehensive set of colour metrics consisting of two average values (one for fidelity and one for saturation), some detailed values and various graphics as a means of displaying the information in an easily understandable manner. TM-30’s fidelity index (Rf ) has the same building blocks as the General CRI: test colour samples, a test light source and a reference light source with the same CCT, various calculations ending with an arithmetic average. By using 99 test colour samples (as shown in figure 2), the most recent and most uniform colour space, a new calculation procedure to scale the calculated value to fit a 0-100 range and a proportional blend of the reference light sources for CCTs between 4500K and 5500K, it addresses some of the CRI’s deficiencies. The average saturation value, called ‘gamut index’ (Rg), complements the fidelity index. It indicates the average saturation change experienced by the test colour samples under a test light source relative to a reference light source with an identical CCT. It is calculated by allocating

While criticism of the CRI was piling up, advances in colorimetry were made and alternative methods and approaches were developed. The emergence of LEDs made this topic more pressing, as anecdotal reports that the General CRI did not correlate well with the visual experience for light sources with narrow-band or spiked spectra started amassing, which was confirmed by the CIE in 2007 [2]. Some proposals addressed the CRI’s deficiencies and therefore ended up being fidelity metrics relatively similar to it. Some advocated a two-measures approach to describing a light source’s colour properties, that is one measure for fidelity and one for saturation. Others went further and suggested the use of graphics rather than single numbers. And again others saw the need to address different audiences with different metrics. All these proposals had one thing in common: none was approved by the CIE. Therefore, due to the lack of an alternative, the CRI continued to be used and the technical content remained unchanged in the CIE’s 1995 CRI publication [3].

Figure 4. Colour distortion graphic [6]

THE ROLE OF TM-30

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February 2018 Lighting Journal

Colour rendering metrics

Figure 5. Chroma change by hue [6]

Figure 6. Colour vector graphic [6]

the test colour samples into 16 hue bins (based on their positions under the reference source at the required CCT) and then by averaging their positions in each bin for the test and reference light sources separately (see figure 3). The gamut index is the ratio of the areas of the two polygons formed by these average positions. A value of 100 indicates no change in saturation, a value smaller than 100 a decrease and a value above 100 an increase. As already mentioned, TM-30 provides detailed values and various graphics in addition to the average fidelity and gamut indices. Changes in saturation can be viewed either graphically or numerically: the colour distortion graphic (figure 4) shows the reference light source as a white circle and the test light source as a coloured area. Where the test light source extends beyond the white circle, those colours are experiencing an increase in saturation; where the test light source lies within the white circle, they experience a decrease in saturation. The same information is displayed quantitatively in a bar chart with the help of the previously mentioned 16 hue bins (see figure 5). Hue shift information is shown in TM30’s colour vector graphic (figure 6). This time the reference light source is drawn as a black circle and the test light source as a red polygon. With the help of the same 16 hue bins, represented by one arrow each, average saturation changes and hue shifts in each hue bin are displayed. The direction of each arrow provides information about what part of the colour shift is due to a change in saturation and www.theilp.org.uk

what part is due to a change in hue. The radial direction of the arrows indicates a saturation change (with the arrow pointing to the centre being a decrease and an arrow pointing away from the centre an increase); the circumferential direction of an arrow indicates a hue shift. In addition to TM-30’s average fidelity index, more detailed fidelity information can be gained by looking at its hue fidelity indices, which relate again to the same 16 hue bins, or even its 99 sample fidelity indices, which relate to the 99 test colour samples, and their corresponding graphics (figures 7 and 8). Plus, TM-30 offers a so-called ‘Skin Fidelity Index’, which is the average value of two test colour samples representing fair and dark human skin tone. As shown above, TM-30’s key advantage is its extensiveness, in other words that it slices and dices and visualises its data resulting in numerous indices and graphics. However, TM-30 also has some limitations. Like the CRI, it is CCT-dependant and therefore a relative measure. It also offers only limited information about hue shifts and lightness levels and changes are practically ignored.

AWARENESS AND USE OF TM-30

As part of my MSc in light and lighting dissertation at the Bartlett, University College London, I ran two small online surveys among UK-based lighting designers and manufacturers in June 2017. Among other things, I explored their understanding and use of TM-30. To my surprise all 13 designers said they were aware of TM-30 and the majority said that they

had already worked with a manufacturer who used TM-30 metrics. However, only three of the nine manufacturers surveyed had already adopted it. The lighting designers rank-ordered TM-30 not being accredited by the CIE, it not being part of a national or regional standard, and resistance from manufacturers as their top three main barriers to its widespread use. The manufacturers agreed with the lighting designers about the first two barriers. However, they ranked the retesting of existing products and the risk that some products will be viewed as ‘downgraded’ as their least important barrier. Now, as the lighting community was unable to agree on a new colour rendering metric for more than 40 years, one could reasonably assume that nothing was likely to have happened in the two years since the publication of TM-30. Wrong. Even the early TM-30 supporters said that it would not be the end of the journey, and so it came about that the CIE published a new colour fidelity index in May 2017 [7]. The 2017 CIE Fidelity Index (also called ‘Rf’) is similar to TM-30’s fidelity index, as it is based on it; in other words it uses the same 99 test colour samples and the same colour space. However, it uses a different reference light source blending range (between 4000K and 5000K CCT) and a different scaling factor to make the average General CRI and CIE Rf values identical. Whereas TM-30’s fidelity index was promoted as a General CRI replacement, the CIE made it clear its new fidelity index

February 2018 Lighting Journal

REFERENCES [1] The SLL Code for Lighting, Raynham P. Society of Light and Lighting, London, 2012. [2] Colour rendering of white LED light sources, Commission Internationale de l’Eclairage, CIE, Vienna, 2007. Report No: CIE 177:2007.

Figure 7. Fidelity indices for each hue bin [6]

was no such thing, and it was labelled as ‘for accurate scientific use’. As opposed to TM-30’s suite of high-level and detailed values and graphics, the 2017 CIE Fidelity Index is an average fidelity index only. Its calculation tool also provides values for each of the 99 test colour samples, but it is purely numeric without a visual aid to link the numbers to colours. Therefore, we now have three different colour metrics: The General CRI, which is simple, widely used and well known, but has inaccuracies and limitations. TM-30, which is more than a fidelity metric and provides different levels of information to different users, but also has limitations and is not supported by CIE. And now the 2017 CIE Fidelity Index, which is supported by the CIE, but is a fidelity metric only

and limited in how it is presented. Finally, that, of course, leaves us to speculate about the future. Ideally, the CIE would develop and publish a comprehensive colour metric set, effectively a CIE equivalent of TM-30, which provides different aspects of colour quality using different means for different users. We might be lucky and head that way, as the CIE has a technical committee working on (a) perception-related colour quality measure(s) beyond fidelity. However, as the publication date is unknown, why not have a look at TM-30 in the meantime?

[3] Method of measuring and specifying colour rendering properties of light sources Commission Internationale de l’Eclairage, CIE, Vienna (Austria), CIE Central Bureau, 1995. Report No: CIE 13.3-1995.

[5] Solid-state lighting technology fact sheet – evaluating color rendition using IES TM-30-15, US Department of Energy – Energy Efficiency & Renewable Energy, 2015. [6] IES TM-30-15 Advanced Calculation Tool v1.02.xlsm [7] Colour Fidelity Index for accurate scientific use, Commission Internationale de l’Eclairage, CIE, Vienna, 2017 Report No: CIE 224:2017.

[4] IES TM-30-15 – IES method for evaluating light source color rendition, Illuminating Engineering Society of North America., New York. IES, 2015.

Janine Stampfli MSc MScLL PMP recently completed her MSc in Light and Lighting at the Bartlett at UCL and is now an aspiring lighting professional

Figure 8. Fidelity indices for individual test colour samples [6]

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February 2018 Lighting Journal

LEDs and blue light

MORE THAN MEETS THE EYE? Where do the ‘danger edges’ lie for blue light, and blue light hazard? Are LEDs really harmful to health? In his presentation to the ILP’s Lightscene CPD event, Alan Grant assessed the recent evidence By Alan Grant

EDs have come a long way in recent years. The multitude of types, efficacies, colour temperatures and colour quality have increased dramatically, and improvements continue to be made. The benefits of LED are vast and well documented. But how much do we really know about this evolving technology, a technology that is moving so fast that neuroscience, photobiology and lighting standards are struggling to keep up? For manufacturers, the LED revolu-

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tion has proved a radical departure from lamp technology and a steep learning curve, but many innovative products would not exist today without it. In some respects, we (the lighting industry) started from the wrong place with early LED technology, particularly in street lighting, where there was an emphasis on trying to match the performance of established lamp technology. Now, as the market is beginning to mature, it’s easy to look back and criticise early LED products, with their

February 2018 Lighting Journal

poor optical control and very high CCT (by today’s standards). Yet this was the only way to achieve the required lumen output and meet the lighting design requirements. Add to this some poor installations – too close to properties, with significant light trespass and no shielding. The result? Unhappy residents and some pretty bad press, particularly in the UK and US, with regards to glare and brightness of LED lighting, potential health concerns and sleep deprivation.

ADDRESSING THE EVIDENCE

In 2016, in the US, a report from the American Medical Association (AMA) entitled Human & Environmental Effects of Light Emitting Diode Community Lighting caused a stir and some backlash amongst lighting professionals [1]. One of its notable conclusions was that the use of colour temperature lower than 4000K ‘will minimise potential health and environmental effects’ (of LED lighting), which fuelled the adverse-press-reports fire.

Also in 2016, in the UK, Public Health England (PHE) published a report commissioned by CIBSE & the SLL entitled Human Responses to Lighting Based on LED Lighting Solutions which covered both interior and exterior lighting [2]. One of its conclusions was: ‘Consideration should be given to reducing the CCT (below 4000K); avoiding potential adverse effects on melatonin production in the evening’. Both reports made recommendations related to colour temperature,

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February 2018 Lighting Journal

LEDs and blue light

but only PHE explained why. In July 2017, one of the two independent scientific committees within the European Commission, The Scientific Committee on Health, Environment and Emerging Risks (SCHEER), which represents the opinion of the independent scientists committee members and several external experts including a leading PHE scientist, published its Preliminary Opinion on Potential Risks to Human Health of Light Emitting Diodes [3]. For lighting professionals, this is perhaps the most relevant report. It is the most recent and it used papers and reports published in international scientific journals, including up-to-date research, in this fast-moving area of science. The committee’s report concluded that: ‘There is no evidence of direct adverse health effects from LEDs emission in normal use (lamps and displays) by the general healthy population. There is a low level of evidence that exposure to light in the late evening, including that from LED lighting and/ or screen may have an impact on the circadian rhythm. At the moment, it is not yet clear if this disturbance of the circadian rhythm leads to adverse health effects.’ The conclusion continued that, ‘there are studies conducted on animals showing adverse effects (of exposure to white LED lighting) raising concerns particularly in the susceptible population (young children, adolescent and elderly people), but that the results obtained in these studies were using exposure conditions that are difficult to relate to human exposure.’ Furthermore, ‘reliable information on the dose-response relationship for adverse health effects for the case of the healthy general public is not available in the scientific literature for all wavelengths emitted by LED devices.’

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SO, ARE LEDs HARMFUL TO HEALTH?

To pick the bones out of this, the headline here is that there is currently no evidence of direct health effects from LED emission in normal use by the general healthy population (my italics). The committee qualifies this statement by identifying those who are not within the ‘general healthy population’ as follows: ‘Vulnerable and susceptible population (young children, adolescent and elderly people) have been considered separately. Children have a higher sensitivity to blue light and although emissions may not be harmful, blue light (between 400nm and 500nm) may be very dazzling and may induce photochemical retinopathy, which is a concern, especially for children below three years of age. The elderly population may experience discomfort with exposure to LED systems, including blue LED display (for example destination displays on the front of buses will be blurred).’

THE EFFECTS ON CHILDREN

From this we can surmise that children, and particularly those under three years of age, are particularly susceptible to blue light. A quote from the SCENIC[DB1] R (European Commission Scientific Committee on Emerging and Newly Identified Health Risks) explains this as follows. ‘A child’s crystalline lens is more transparent to short wavelengths than that of an adult, making children more sensitive to blue light effects on the retina’ [4]. A quick look at Wikipedia defines photochemical retinopathy as: ‘damage to the eye’s retina, particularly the macula, from prolonged exposure to solar radiation or other bright light, eg lasers or arc welders. The term includes solar, laser, and welder’s retinopathy and is synonymous with retinal phototoxicity. It usually occurs due to staring at the sun, watching a solar eclipse, or viewing an ultraviolet, Illuminant D65, or other bright light’ (my italics) [5]. Anyone who has welded or studied welding will be aware of the term ‘arc eye’, which is photo-retinopathy.

THE AGEING POPULATION

It is well-known and well-understood that the human eye degrades over time. This is evident in the large proportion of those aged over 40 who require glasses for reading, distance vision or both. The bad news therefore contained in the report is that elderly people may experience discomfort with exposure to LED systems, including blue LED displays (which may include white LEDs with a high colour temperature and therefore

February 2018 Lighting Journal

typically a blue light content) making it difficult to read. With the passage of time, the proliferation of LED-illuminated displays or signs will only increase. We know that the proportion of over-60s in the UK population is also increasing. At present about 25% of the population is aged over 60, or the equivalent of 15.3 million people. By 2035, this is predicted to be 29%, or around 21 million people. The statement from SCHEER is therefore not great news for this ‘vulnerable and susceptible’ population.

KEY TAKEAWAYS

There are a few other statements from the body of the SCHEER opinion that are worthy of note for lighting professionals. ‘Many people perceive white 4,000K LED lighting as harsh because almost 30% of the spectrum is emitted as blue light’. We can dissect this statement word by word, and I’m sure many readers will do just that. For me, the colour of white light is subjective, and application should play a part in the user’s choice of colour temperature. One person’s ‘harsh’ is another person’s ‘clean’ or ‘bright’. Many people prefer a ‘whiter’ light (say 4000K) in a kitchen or workshop and a warmer colour (say 3000K) in a living room. The percentage stated (30%) is not common between different LED sources, and so is highly questionable. ‘There are several variables to be taken into account when referring to the effects of optical radiation from LEDs on human health: 1. Spectrum of a LED light source 2. Intensity of the lighting, especially in the blue band 3. Duration of exposure 4. Health of the eye 5. Direct staring without deviation versus active eye movement’ Taking these points one at a time, the spectrum of an LED light source (1) in full is the spectral power distribution of the light source (SPD). This is illustrated as the combination of the range of wavelengths within the visible spectrum that produce the colour of light perceived by the human eye. Note that the CCT of a light source is not mentioned in this list, although it was mentioned in both the AMA and PHE’s recommendations and in the SCHEER statement above, with regards to perception of harsh lighting. The reason for this is simple. With very few exceptions, those in the lighting indus-

try refer to the colour of the white light emitted from an LED (or other) light source in terms of CCT: 4000K, 3000K, 2700K for example. It’s a simple and well-understood means of communicating the appearance of the colour of the light but, there is no correlation between CCT and SPD. Light sources of the same CCT can have different SPDs and those with the same CCT can look different, so CCT is only a rough guide of the actual spectral content of a light source. Let’s address this statement starting with point 1. Clearly, the SPD of a light source will be important to the effect of optical radiation, as it is well understood that emissions of part of the visible spectrum influence brain stimulus. The intensity of light (2) is again self-explanatory. A bright light source will have a different, potentially stimulating, effect on human physiology than a very dim light. Relatively low-intensity levels (<100lux) have been reported to affect the circadian system (Glickman, Levin et al. 2002) [6]. The duration of the exposure (3) is again something we can all probably relate to and even short durations (seconds to minutes) can have an effect on circadian system (Glickman, Levin et al. 2002). The health of the eye (4) covered earlier in this article (children’s lenses not being fully developed and the lenses in the eyes of elderly people hardening (from middle age onwards) resulting in difficulty to focus). Direct staring without deviation versus active eye movement (5) can lead to photo retinopathy, described earlier and affect the circadian system.

INFLUENCING THE CIRCADIAN RHYTHM

I’ve mentioned circadian rhythm and circadian system above and the statement www.theilp.org.uk

February 2018 Lighting Journal

LEDs and blue light

Referring back to the 2016 PHE report mentioned earlier in this article, this states that: ‘Consideration should be given to reducing the CCT (below 4000K); avoiding potential adverse effects on melatonin production in the evening’. The two reports – PHE and SCHEER – therefore appear to be aligned in their research, but not in their conclusions.

within the SCHEER opinion: ‘Short-wavelength light (peak around 480nm) influences the circadian system’ also raises the issue of it being affected by light within the blue part of the spectrum. The presence of a light (day) and dark (night) phase due to the earth’s rotation has resulted in the evolution of an internal clock in almost all organisms, including humans, as SCHEER makes clear. This biological timekeeping system influences the timing of our sleepiness, hunger and willingness to be active through to unconscious physiological patterns, such as the preparation of internal organs for daily activities and the ‘decision’ to wake from sleep, immune response and energy metabolism. Ambient light levels are the main information our bodies use to synchronise themselves (Andersen 2012) [7]. There is a body of evidence to support that chronic impairment of the circadian system has been shown to compromise health in many ways: sleep and cognitive impairment, psychiatric disorders, gastrointestinal disorders and breast cancer (Knutsson 2003, Kecklund & Alexsson 2016) [8]. Therefore, the statement from SCHEER that ‘Short-wavelength light (peak around 480nm) influences the circadian system’ should be taken seriously. As well as the image-forming function of our eyes, there are cells within human and other mammalian eyes that perform non-image forming functions including pupillary light reflex. Called intrinsically-photosensitive retinal ganglion cells (ipRGC), these also relay light information to the part of the brain (the suprachiasmatic nucleus of the hypothalamus) that controls the biological clock. This, in turn, initiates signals to other parts of the brain to release hormones (for example melatonin and cortisol) related to daily activities as outlined above. The ipRGCs contain a photopigment called melanopsin with a peak sensitivity of 480490nm (Lucas 2014) [9] which is why the S C H E E R m a d e t h e st a t e m e n t : ‘Short-wavelength light (peak around 480nm) influences the circadian system’. www.theilp.org.uk

CONCLUSION

In summary, the latest research from an independent scientific body (SCHEER) states: ‘There is no evidence of direct adverse health effects from LEDs emission in normal use (lamps and displays) by the general healthy population. There is a low level of evidence that exposure to light in the late evening, including that from LED lighting and/or screens, may have an impact on the circadian rhythm. At the moment, it is not yet clear if this disturbance of the circadian rhythm leads to adverse health effects.’ It goes on to say: ‘Since the use of LED technology is still evolving, the Committee considers that it is important to closely monitor the risk of adverse health effects from long-term LED usage by the general population.’ There are hundreds, possibly thousands, of research papers and articles on this subject and the number is steadily growing. There is, however, insufficient research and evidence for experts to draw clear and concise conclusions on this complex and relatively new subject. Its impor-

REFERENCES [1] Human & Environmental Effects of Light Emitting Diode Community Lighting, American Medical Association, 2016, https://www.ama-assn. org/sites/default/files/ media-browser/public/ about-ama/councils/ Council%20Reports/ council-on-science-publichealth/a16-csaph2.pdf [2] Human Responses to Lighting Based on LED Lighting Solutions, Public Health England, SLL, CIBSE,

April 2016, http://www. lightmare.org/docs/PHECIBSE-SLL_LED_report_ May2016HRLBL-b.pdf [3] Preliminary Opinion on Potential Risks to Human Health of Light Emitting Diodes, European Commission, The Scientific Committee on Health, Environment and Emerging Risks, 06 July, 2017, https://ec.europa.eu/ health/sites/health/files/ scientific_committees/ scheer/docs/ scheer_o_011.pdf [4] http://ec.europa. eu/health/scientific_

tance cannot be underestimated though. LED lighting is a recent revolution which is sweeping the globe for many good reasons, but it is in its infancy. SCHEER has identified the ‘vulnerable and susceptible population’ to be outside the core statement, ‘no evidence of direct adverse health effects from LEDs emission in normal use’. We’ve only been exposed to LED emissions for a small number of years, after previous exposure to other types of light sources. As the years pass, today’s toddlers will become adults who will have only been exposed to LED lighting. The ever-increasing ageing population will have had exposure from a far younger age. Manufacturers, designers, specifiers and installers – we all have our part to play as lighting professionals. We should all take care with the application of this technology, ensuring that good lighting control, appropriate distributions, shielding, dimming, colour temperature and other facets of LED lighting are used responsibly and proactively. It is too simplistic simply to choose a 3000K (or lower) colour temperature without consideration to the SPD of the light source. This has always been the case with lighting, before the LED revolution as well as today. But it has never been more important for our industry and the general population, both healthy and susceptible.

Alan Grant is design and development director at DW Windsor

committees/emerging/ docs/scenihr_o_035.pdf [5] https://en.wikipedia. org/wiki/Photic_ retinopathy [6] Ocular Input for Human Melatonin Regulation: Relevance to Breast Cancer, G Glickman, R Levin and G C Brainard. Neuroendocrinology Letters, 2002, 23 Suppl 2: 17-22. [7] A Framework for Predicting the Non-visual Effects of Daylight – Part I: photobiology-based model, Andersen M, Mardaljevic J

and Lockley SW (2012). Lighting Research and Technology, 44(1), 37-53. [8] Health disorders of shift worker, Knutsson, A. Occup. Med. 53, 103-108 (2003). https://doi.org/10.1093/ occmed/kqg048 [9] Measuring and Using Light in the Melanopsin Age, Lucas RJ, Peirson SN, Berson DM, Brown TM, Cooper, HM, Czeisler CA, Figueiro MG, Gamlin PD, Lockley SW, O’Hagan JB, Price LLA, Provencio I, Skene DJ and Brainard GC (2014). Trends in neurosciences, 37(1), 1-9.

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February 2018 Lighting Journal

Light and circadian rhythms

minous Pattern’ corridors and one 4m entrance wall, which have been designed to mimic the effect of a twinkling night skyview of a city as a plane comes in to land.

PERSONALISED LIGHTING

EXECUTIVE PERKS

A new executive lounge at Oslo’s Gardemoen Airport uses architectural tuneable LED lighting that can help passengers to work, relax or even, it is argued, beat jet lag

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he existence of a third photo-receptor system in the eye, photosensitive retinal ganglion cells that help to govern our body clocks, was at the heart of Professor Russell Foster’s ILP International Year of Light lecture in 2015 (‘Body Language’, Lighting Journal, October 2015, vol 80, no 9). Our understanding of how our circadian rhythms work and what affects them is evolving all the time, not least the impact of light and lighting in this context. Nevertheless, lighting professionals are trying where they can to develop lighting solutions that help, especially for those crossing time zones. One of the latest is at Oslo’s Gardemoen Airport in Norway, where Philips Lighting has installed architectural tuneable LED lighting that, the company argues, can help passengers to beat jet lag. The connected lighting system in the new Scandinavian Airlines Systems (SAS) ‘Experience Lounge’ was unveiled to the public at the end of September. It has nine separately lit areas, all catering to those travelling with the airline in various business or premier categories. Visitors are welcomed by two 11m ‘Lu-

There is a ‘wellness room’ – where travellers can get a massage if they so wish – and an ‘innovation hub’, the latter incorporating five Philips Lighting ‘Luminous Textile’ panels, which combine Kvadrat Soft Cells (patented panels that control sound absorption) with interwoven multi-coloured LEDs. Three rooms have then been equipped with Philips Lighting’s Hue product, which allows travellers to personalise their own light settings. There are six settings to choose from, ranging from dimmed warm and relaxing ‘night’ through to a morning-style ‘Savannah’, through to a relatively self-explanatory ‘energise’. There is also ‘read’, ‘concentrate’ and ‘party’, for (one has to assume) those travellers who really want to make the wait for their journey a memorable experience. A further room is what is called the ‘Daylight Booster’ room. This is a curtained-off area when you can sit with your laptop or coffee while a fabric-covered wall baths you in 6500K light. The light comes from LEDs located behind the translucent cloth and, while it is possible to dim the output, the very blue colour temperature remains constant. The cloth can double-up as a low-resolution video screen fed wirelessly from a laptop. Finally, there is a bar and dining area kitted out with StyliD spots, and a reading and relaxing area with Philips Lighting’s LuxSpace accent lights. ‘Light plays an important role on how people actually feel,’ said Astrid Simonsen Joos, market leader for Philips Lighting Nordics at the launch of the new lounge. ‘We wanted to create a positive and memorable experience in the new lounge. Our lighting concept aims to energise guests before they travel or offer them a space to relax and recharge,’ she added.

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February 2018 Lighting Journal

Solar energy

ow is it that in this day-and-age of smartphones and self-driving cars more than 1.2 billion people still lack access to electricity? That question, and fighting towards the solution, is what keeps the staff of SolarAid, a ten-year-old UK charity, up at night. In Africa, where SolarAid works, night falls early and the only light available to 600 million people is the flickering, toxic and highly polluting flame of the kerosene lamp. It is hard for most of us in the developed world to truly imagine what that’s like. The closest most of us get is when we go camping, armed with a car-load of creature comforts, most notably a nice bright www.theilp.org.uk

torch. But for the people of rural Africa, electric lighting is a dream. Millions of African children do their homework by the flicker of a naked kerosene flame, breathing in black-carbon whilst they study.

THE ‘SUNNYMONEY WAY’

In some areas change is coming, albeit slowly and with hard-won progress, although it’s not through lack of trying. SolarAid’s model is different to other charities. SolarAid exists to kick-start solar markets while at the same time using philanthropic funding to fund its retail operation, SunnyMoney. In a nutshell, SunnyMoney sells solar lights to African people without making a net

profit, which means the African entrepreneurs can then resell the lights for a profit. This achieves a four-fold effect. First, it creates jobs; second, it gets solar lights into the hands of end users; third, it triggers cash savings for rural Africans; and fourth, it helps to ‘catalyse’ solar markets. For those unfamiliar with the term, a catalysed market is one where more than 10% of kerosene lamps have been displaced. This, in turn, creates opportunities for commercial companies to come in and grow the market still further. SolarAid catalysed its first two African solar lighting markets between 2012 and 2015, in Kenya and Tanzania. Key organisations within the solar light-

February 2018 Lighting Journal

ing industry, not least the Global Off Grid Lighting Association, have recognised the difference we have made on the ground and are backing us to repeat this success in Africa’s 50 as-yet uncatalysed markets. In purely economic terms, the maths behind the replacement of kerosene with solar lights seems like an absolute no-brainer. Let’s look at how it works in more detail. When either we through SunnyMoney or any of the 100-plus solar lighting companies operating in East Africa sell solar lights to rural Africans, this frees huge savings for that buyer. That may not sound like much to you or I. But many of our buyers are people trying to live on little more than a $1 a day. $225 is therefore potentially a huge sum, a saving that can be spent on food and other necessities, and all at a time when famine is stalking the continent. Bloomberg New Energy Finance and Lighting Global has calculated that $27bn a year is spent by the 1.2 billion people without grid electricity on lighting and phone charging using kerosene, candles, battery torches and other fossil-fuel powered means [1]. To put that number into perspective, Jeremy Leggett, founder and chairman of SolarAid, has calculated in his latest ebook The Test that it would cost a maximum of $2bn to provide clean light to each and every one of the world’s 1.2 billion people without grid electricity. That’s, of course, just 28% – so a little over a quarter – of just the annual subsidy going to kerosene for lighting. And it is a mere 7% of the $27bn global amount spent each year on non-solar lighting.

SUSAN’S STORY

Realising the huge potential savings for African families is hard but rewarding work. Since its inception, SunnyMoney has helped numerous agents develop micro-businesses to supplement their income whilst spreading clean, renewable light throughout rural communities. Susan, from Yumbe District in Uganda, is a mother, student, teacher, farmer businesswoman and now a SunnyMoney agent. She heard about SunnyMoney when she attended a school campaign workshop and immediately decided to buy some solar lights to distribute. She was attending a class in administrative law and so her first clients were her classmates. ‘My fellow students were impressed by the benefits I have gotten from using the small lights, and bought everything I had, including my own personal light,’ explains Susan. She quickly placed another order and, by the time the next school session started, her fellow students had done all the marketing she needed. ‘All the students bought the lights I had and those who held back because of financial difficulties, I took down their phone numbers for a follow-up,’ she says. She has now recruited more than 10 subagents, who help her access hard-to-reach communities. She has used her profits to open up a shop selling farm produce. Her next dream is to buy a plot of land and start a small SunnyMoney shop. Susan’s example is one of many that illustrates the multiple positive effects of the SolarAid/SunnyMoney model. With more support from the developed

world, I am confident that one day I may be able to, in effect, do myself out of a job by ensuring the charity side of this process, SolarAid, is not needed any more; that the transition to solar is self-supporting and self-sustaining. More importantly, I look forward to the day whereby this success will mean that everyone has access to clean, renewable light rather than being forced to rely on toxic kerosene lamps. ¢

Oliver Sylvester-Bradley is marketing manager at SolarAid. To find out more about the charity’s work, or to make a donation, go to www.solar-aid.org

REFERENCES [1] Off-grid solar market trends report 2016, Bloomberg New Energy Finance and Lighting Global, https://about.bnef. com/blog/off-grid-solarmarket-trends-report-2016/

www.theilp.org.uk

February 2018 Lighting Journal

Lighting in healthcare

PATIENT EXPECTATION Reducing energy and maintenance costs were important factors in a US healthcare company’s decision to switch to LED. But fewer slips and trips and a better environment for patients and staff alike were also high on the list By Nic Paton

riginally founded in 1914, McLaren Health Care in the US covers 6.5 million residents around the environs of Michigan and Detroit, with care being delivered from 11 primary hospitals. These hospitals have recently undergone an LED facelift, installing 25,000 LED fixtures as well as intelligent lighting controls, an investment that it has calculated should save the healthcare company some $1.6m a year, with $1.25m of that coming from energy savings alone. The better lighting system is also expected to lead to a better patient and workforce environment, with lower noise levels and fewer falls just two of the benefits. The project was driven by Keith Miller, www.theilp.org.uk

corporate facilities manager at the 3,096bed organisation, and who a year ago tasked lighting company Cree to oversee the refurbishment project.

INTENSIVE LIGHTING AUDIT

The project involved, first, an intensive 45day audit on the existing lighting in each of the 11 hospitals, including evaluating every area, counting all fixtures, fittings and lamps, and analysing wattage and application. One challenge was that, like all hospitals, the project was going to need to be completed in complex, ‘always on’ facilities that were working to tight schedules, where disruption and noise would need to be kept to a minimum and where space was a premium.

There was also an important education and communication element required to help employees understand and get behind the project and the likely disruption it was going to cause to how they worked, with Cree even donating thousands of LED lamps to staff as a token of appreciation. The installation was then carried out in a phased approach, first replacing exterior fixtures in parking lots and structures, walkways and other outdoor campus areas. Then it was a question of moving inside. Contractors were trained in how to install the various fixtures and Cree was invited to train on the set-up and commissioning of its SmartCast intelligent lighting controls. With more than 20 fixtures specified in the upgrade, a colour-coded label system

February 2018 Lighting Journal

was developed so that electricians knew which fixtures to install where. So, what have been the results? Feedback from staff, visitors and patients has so far been positive, argues Keith Miller. ‘We’ve seen a tremendous amount of compliments and assurance from staff and family members that they feel a lot safer on property at night. When you tell them that energy consumption is actually reduced and you are still providing better light, they get excited,’ he explains.

BETTER ILLUMINATED AREAS

Comments include that the lighting at parking sites and within stairwells is now brighter, and hallways seem much better

illuminated without the ‘cave effect’ created by the previous parabolic lighting. This has also made life a lot easier for the cleaning staff. The ability to dim the fixtures was an important part of the McLaren’s noise reduction strategy. ‘We can dim the lights down at 8pm to let everyone know this is a time to be quiet so people can rest appropriately,’ explains Keith Miller. There also has been a positive effect on the risk of slips and falls. ‘You have people with various injuries or conditions who may have walkers or wheelchairs, so having proper lighting is an important preventative measure,’ he adds. As with any transition to LED, there have been significant maintenance and facilities

management savings, both in internal areas but also external parking and estate areas. There have also been savings in not having to keep so much replacement stock. ‘We don’t have a lot of storage space, and the upgrade dramatically reduced the inventory we need on site and the number of different lights. Some of the hospitals still used the old T12s and those are getting hard to come by,’ he says. And this is before the expected savings to come over time from reduced energy usage. As Keith Miller concludes: ‘First impressions are very important for a patient and for their families. We want them to have a consistent experience from one McLaren hospital to another and lighting is an opportunity to show that.’ www.theilp.org.uk

February 2018 Lighting Journal

Lighting in education

CAMPUS LEARNING 36

Lincoln College has reduced its energy and maintenance costs, become more environmentally friendly and created a more dynamic, engaging learning environment – all by tapping into Salix Finance to help fund a transformational lighting upgrade By Craig Mellis

pgrading lighting systems is being seen by many within the public sector as a key way both to reduce outgoing spend in the current financial climate and to minimise environmental impact in an increasingly energy-conscious environment. However, as ILP Senior Vice President Colin Fish highlighted last year (‘Money talks’, Lighting Journal, October 2017, vol 82 no 9), you can only do this effectively if you fully understand the different options available to you to fund such projects. One important funding channel – and identified by Colin within his article – is Salix Finance, the government-backed lending company set up in 2004 to provide interest-free loans to the public sector to improve their energy efficiency, reduce carbon emissions and lower energy bills. This article intends to show how one further education provider, Lincoln College, did just this – how it used Salix Finance to unlock the funding for a transformational lighting upgrade. More than 7,000 outdated light fittings have been upgraded in 23 buildings across the college group’s three campuses in Lincoln, Newark and Gainsborough, and the college is set to save tens of thousands of pounds and significantly reduce its greenhouse gas emissions as a result.

LOWER ENERGY AND MAINTENANCE

Indeed, the new lighting infrastructure is set to cut the college’s energy costs by more than £165,200 per year and reduce carbon emissions by over 605 tonnes annually. In all, the upgrade is set to reduce the college’s energy costs by some 70%, equating to a 1.5 GWh saving. Alongside this, the new scheme has the www.theilp.org.uk

added benefit of reduced general maintenance costs – in all, an estimated £3.3m over the lifetime of the upgrade – as the bulbs will need to be changed less often. The project took around eight months, and was completed last March. It involved the replacement of inefficient T12 and T8 fluorescent light fittings with more modern LED luminaires, which have also helped to create a more comfortable working environment for students and staff. Where Salix Funding came into play was by providing more than £704,000 worth of interest-free funding. The funding for the project was provided via The College Energy Fund, a partnership between Salix Finance and the Environmental Association for Universities and Colleges, and supported by the Association of Colleges.

FIVE-YEAR BREAK-EVEN

The school will repay the cost of the project from the savings recouped from the reduced energy bills, with the scheme expected to break even in under five years. Once the loan is repaid, the school will, naturally, continue to benefit from the annual savings, meaning the financial impact of the upgrades for the school is minimal and that funding can be used elsewhere. Finally, from a lighting perspective there has been one other vitally important benefit – an improved learning environment for the college’s 11,000 students, as Rachel Newton, group head of infrastructure, facilities and estates at Lincoln College, explains ‘Aside from the financial and carbon savings resulting from the reduction in electricity usage, we are also benefiting from considerably improved lighting levels throughout the college buildings. Each of our campuses now has a much lighter and brighter teaching environment for students and staff, which have been welcomed by all. ‘Working with Salix has greatly assisted us in achieving our energy reduction strategy, enabling us to replace the lighting much sooner and on a larger scale than would have otherwise been possible,’ she adds.

Craig Mellis is programme manager, universities and colleges, at Salix Finance

February 2018 Lighting Journal

Light + Building 2018

TOMORROW’S WORLD? The so-called ‘smartification’ of everyday life – automation, connectivity and security – will be a key focus for next month’s Light + Building international lighting fair in Frankfurt

omorrow’s trends in the home’ will be one of the key themes for next month’s Light + Building international light fair in Frankfurt, Germany. The biennial show, which will run from 18-23 March, will once again have a ‘Trend Forum’ as its centrepiece, which will aim to showcase key trends in lighting in the home for the 2018/2019 season. The motto for this year’s show will be ‘Connected – Secure – Convenient’ highlighting that, naturally, smart and connected lighting technologies are set to be a central part of this discussion, as well as smart networks and, increasingly, electronic security technology. In fact, the show is set to highlight what www.theilp.org.uk

the organisers, Messe Frankfurt, have called the ‘smartification’ of everyday life. Within this, how home and building automation can be merged with electronic security technology is set to be another important talking point, with a special ‘SECURE! Connected Security in Buildings’ show. Video monitoring and access control technologies, and their interconnection and integration within building automation, will be very much in evidence. In fact, in parallel to Light + Building (and also located in Hall 9.1), the Intersec-Forum, or the annual conference on networked security technology, will be taking place from 19-23 March 2018.

February 2018 Lighting Journal

MOOD AND WELLBEING

Another area of focus for this year is the notion of ‘aesthetics and wellbeing in harmony’ or, in essence, how lighting can evoke emotions and affect mood and a sense of wellbeing, in particular the growth and ubiquity of human-centric lighting. Design consultants from the bora.herke.palmisano studio will offer a series of daily lectures, with subsequent guided tours, on these and other areas. To complement the Trend Forum, there will be ‘Trendspot Design’ in Hall 1, which will offer an opportunity for lighting professionals to get a targeted overview of technical, design-orientated lighting and luminaires.

More generally, the show will, as ever, be an opportunity for networking and getting together with fellow lighting professionals. In 2016, it was attended by a record 216,000 trade visitors from 160 countries. This year 2,600 exhibitors are also expected to launch lighting, electrical technology and house and building automation products at the show. ‘Light + Building is the setting for big ideas and decisive impulses. Accordingly, we are delighted with the positive exhibitor response and are sure the coming edition of Light + Building will again underscore its unparalleled function as the leading trade fair for the sector,’ said Wolfgang Marzin, chief executive of Messe Frankfurt.

WHAT YOU NEED TO KNOW WHAT: Light + Building 2018 WHERE: Messe Frankfurt WHEN: 18-23 March HOW: register for tickets at https://light-building. messefrankfurt.com/frankfurt /en.html#ticket

www.theilp.org.uk

February 2018 Lighting Journal

Light on the past

GAS POWER

Once the electric lamp arrived, it is easy to assume that gas for lighting was quickly swept away by the march of this exciting new technology. In reality, however, gas lighting hung on tenaciously throughout the 1930s

By Simon Cornwell

ooking back at the transition to any new technology, it is all-too-easy with the benefit of hindsight to assume that the shift from one to the other was seamless, an historical inevitability. Take the transition from gas to electric lighting. The assumption is that, after the introduction of the electric lamp, gas was on the back foot, with gas installations being swept away by the march of this new electrical technology. The coming of the discharge lamp, and its vastly improved efficacy, only accelerated this cull as lighting authority after authority succumbed to its greater efficiencies, vastly decreased maintenance responsibilities and just the sheer lustrous temptation of the electric lamp. However, the reality was extraordinarily different; this narrative of inevitable change doesn’t hold up. In fact, by the 1930s, gas was tenaciously holding on, vying with electricity in many districts, and gas manufacturers were proudly proclaiming radical advancewww.theilp.org.uk

ments with dramatic new designs. Mr Therm, the cartoon mouthpiece of the Gas Council, regularly extolled new installations and exciting improvements. So, what was going on? It is reasonable to consider gas street lighting as a strictly 19th century affair; the first gas lanterns, with their primitive fishtail burners which produced their sooty yellow glow, appeared in the first decade. Efficiently burning gas was out of the question as the resulting blue flame gave little light; so an inefficient, oxygen-choked burn was needed to coax the unburned carbon to glow in the heat of the flame. The invention of the mantle, in the dying years of Victoria’s reign, liberated the gas lantern and allowed it to cook on high. The efficient and hotter blue flame heated up the mantle, which then took on the responsibility to irradiate visible light. This invention was timely, as it allowed gas to complete with the new electrical filament lamps which were just starting to appear.

SLOW SPREAD OF ELECTRICITY

Gas continued to be popular in the first few decades of the 20th century. Much of this was due to its engrained monopoly, as electricity was slow to spread into some areas where gas already had a stranglehold. Other installations remained intact and immune due to ingrained inertia from lighting engineers and authorities who were reluctant to change. Other devious authorities played the local gas concern and electricity undertakings off against each other, driving contract prices through the floor, and switching to the cheapest offering. The first electrical lighting installation in Godalming was infamously switched off and replaced by gas when the local gas board made a better offer. Yet gas didn’t remain inert or trapped in its 19th century origins. Firms such as Sugg, Parkinson and Keith And Blackman continued researching the possibility of coaxing extra lumens from gas hydrocarbons. This led to a range of more efficient lanterns with new, novel optical systems. And subsidiary manufacturers, such as

Keith And Blackman’s Magnalux was unveiled just before the Second World War. Thorough mixing of the combustible gases was achieved by pumping it through the enormous exposed pipes attached to the lantern’s canopy

February 2018 Lighting Journal

Sugg was sly when advertising its enormous London lantern, never showing it in-situ and always depicting it as small and insignificant in its illustrations. In reality, it was enormous and bulky, taking between six and 12 mantles. The 8000 was Sugg’s take on the popular wing-type lantern but it was a delicate and fussy design unlike its electrical counterparts

Horstmann and The Automatic Light Controlling Company, refined clock controllers and glow-starters, so gas could enjoy the same level of control as its electrical cousin. The first development after the mantle was the high-pressure gas lamp, which was developed by Keith And Blackman. With a luminous capacity to match the highest wattage tungsten lamps, and a new lozenge-shaped mantle (which was more suited for producing directional beams), it was marketed as a viable competitor to electricity for main roads. But it was only installed in some London districts, as the system required separate high-pressure mains and pumping stations positioned along its route to provide the extra pressure. Despite a large network through central London and the southern suburbs, the system remained somewhat of a pipe dream. The generous dimensions of the gas lantern – in some cases oversized to stop heat conduction melting the solder which held the frame together – provided ample space for an optical system. With the advent of the scientific foundation of street lighting in the 1920s, and its refinement with the discovery of the theory underpinning ‘the mechanism’ in the 1930s, then lanterns could be modified to support these new ideas.

INVENTIVE DESIGNS

Reflectors in the form of facetted stainless-steel sheets could be cupped around the mantle clusters, whilst glass ring and dish refractors could be positioned a safe distance from the burners. Both focused the light from the mantles into high-elevation main beams, providing a more refined output from the mantles. Some of the gas manufacturers took a further step forward, playing with the lines and styling of the lanterns, liberating them from their standard Windsor and Rochester type patterns. By the mid1930s, new ranges started to appear, which departed entirely from their older romantic, chocolate-box origins. www.theilp.org.uk

February 2018 Lighting Journal

Light on the past

The emphasis for Poles Limited in this 1936 advert was marketing its Adastra metal columns. However, the advert captured an uncommon sight of gas lighting (in this case, the Maxill by Parkinson) replacing an earlier installation of electric lighting on the Wolverhamton-Birmingham main road

Sugg was the most inventive, with several new lantern designs. Its 8000 was modelled on the wing-type lantern, with central pendant gas burner surrounded by two large reflective wings. But it couldn’t shake off the stigma that, when compared to its electrical counterparts such as the ESLA Bi-Multi, then it looked fussy, fragile and over-engineered. At the other end of the scale was the Sugg London, a 12-burner monstrosity which more resembled an electric fire than a delicate piece of optical equipment. Sugg probably realised this, as its advertisements for the lantern never featured street scenes and illustrations of the lantern were always small and lost in the graphics and blurb. Despite its swarthy dimensions, the Sugg London was popular, and installed along main roads and high streets, where high-wattage tungsten or the new discharge lamps should’ve been found. The company was also at the forefront of experimentation with the Folkestone lantern. The optical system included a complete cut-off at the horizontal with an axial beam intensity at angles between 60 and 70 degrees. The use of cut-off was limited by the 1937 Ministry of Transport Final Report, which made non-cut-off systems more economical despite their increased glare. But a limited number of electrical companies produced cut-off designs, often tagging them as ‘glare free’ or ‘high visibility’. I believe Sugg’s offering was unique for gas lighting, and was probably designed with an eye on the European market, where cut-off was far more common. Sugg was not alone with its revolutionary new ideas. Competitor Parkinson was also happy to push the frontiers and produced its own impossibly enormous designs.

INTERRUPTION OF THE WAR p

Maxill’s gas lanterns had traditional lines, but both their square and pendant pattern lanterns were fitted with extensive ‘Multiray’ faceted stainless-steel (or ‘Staybrite’) reflectors. It also opted for clusters of mantles to increase the light output

www.theilp.org.uk

Notable was the Maxill range of lanterns which, from a distance, looked like traditional square-type gas lanterns. But they featured two pairs of burners positioned at the foci of two facetted paraboloid reflec-

tors of anodised aluminium. This arrangement cut the lantern in half optically, the two sides providing each of the main beams for road lighting. Like Sugg’s London lantern, the Maxill enjoyed some popularity in the pre-war years despite its massive size and dominating daylight appearance. Special mention should go to Keith And Blackman’s Magnalux, which appeared just before the war. Focused on increasing the efficiency of the lantern, Keith discovered that a more thorough mixing and heating of gas and oxygen increased the yield. To achieve this, he created a lantern with an elongated chimney, and two enormous protruding pipes, which allowed the gases to be thoroughly mixed before entering the mantles. This design probably pushed the limits of what was visually acceptable, and the only installations of this type of lantern were in Woburn Place and Russell Square in London. The Magnalux, Maxill, 8000 and others amply illustrated how the gas industry was actively researching and developing new ideas and designs. Sugg, Parkinson, Keith And Blackmann and others jostled for position in the advertisement spaces, shared exhibition stands at various shows, and shouted out about important new wins in the trade press. It looked like the coming decades, and the improvements in electrical discharge lamps, could do little to dent the enthusiasm of the older technology of the gas lantern. It would have been interesting observing the industry evolving if the Second World War had not interrupted this momentum. But, as the authorities prepared for war, and turned off their gas lanterns, the expectation was that they would be relit after hostilities and gas would continue to be a viable alternative to the electric lamp. The outcome, of course, was quite different. But for a small number of decades in the early half of the 20th century, it was certainly the case that gas was striking back.

February 2018 Lighting Journal

News from the ILP

CALL FOR SUMMIT PAPERS

L 44

ILP BRINGS CPD TO HONG KONG

www.theilp.org.uk

he ILP in November ran a course on exterior lighting design for the Hong Kong government, one of the Institution’s first forays to extend its brand and profile into the Far East. The course, the International Exterior Lighting Design Certificate, was co-written and delivered by ILP technical services manager Peter Harrison and VP education Anthony Smith to members of the Hong Kong government’s highways department. The connection between the Hong Kong government and the ILP arose after two of the highways team successfully completed the ILP’s exterior lighting diploma course in the UK. The week-long CPD proved a huge success, as ILP operations manager Jess Gallacher explained. ‘This was a major project and very successful. We have built strong links with the Hong Kong government, which can be developed in future,’ she said. Peter added that it had been an ‘honour’ to participate. As well as creating valuable link between UK and Chinese lighting professionals, the course served to provide the engineers and technical officers who attended with valuable background knowledge, he added.

ighting professionals have until the end of this month (February) to apply to present at this year’s ILP Professional Lighting Summit. The Summit will take place between 13-14 June at The Oxford Belfry, near Thame in Oxfordshire. The ILP is looking for presentations simply around interesting topics, case studies or expert knowledge, but they must be exclusive and not have been presented publicly prior to the Summit. Lighting professionals should contact Jo Bell on jo@theilp.org.uk with their name, role and organisation, full contact details, the proposed title of the paper, and a 250-500 synopsis of their proposal, to allow it to be reviewed. The deadline for submissions is Wednesday 28 February. More details can also be found online at www.theilp.org.uk

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