Light Lines November/December 23 by Matrix Print

The Society of Light and Lighting

VOLUME 16 ISSUE 6 NOVEMBER/DECEMBER 2023

PRECISION TOOL Why TM65.2 is vital

RELIGHTING HISTORY

Heritage and the circular economy

Editorial

November/December 2023

FROM THE EDITOR SECRETARY Brendan Keely FSLL bkeely@cibse.org EDITOR Jill Entwistle jillentwistle@yahoo.com COMMUNICATIONS COMMITTEE: Andrew Bissell FSLL James Buck Iain Carlile FSLL Jill Entwistle Fiona Fanning Debbie-Sue Farrell Chris Fordham MSLL Rebecca Hodge Stewart Langdown FSLL Luke Locke-Wheaton Rory Marples MSLL Linda Salamoun MSLL All contributions are the responsibility of the author, and do not necessarily reflect the views of the society. All contributions are personal, except where attributed to an organisation represented by the author.

COPY DATE FOR LL1 2024 IS 14 NOVEMBER PUBLISHED BY The Society of Light and Lighting 222 Balham High Road London SW12 9BS www.sll.org.uk ISSN 2632-2838 © 2023 THE SOCIETY OF LIGHT AND LIGHTING The Society of Light and Lighting is part of the Chartered Institution of Building Services Engineers, 222 Balham High Road, London SW12 9BS. Charity registration no 278104

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Given that the SLL has a reputation for being a major repository of lighting knowledge – its Code for Lighting has long been considered almost biblical in authority – it would perhaps be forgivable if the image it conjured up was that of a dusty Gormenghastian library. It is a vision often associated with institutions and venerable bodies. But what is clear from the content of this issue is just how many different areas the SLL works in, not only to acquire and initiate that knowledge, but also to engage people in order to share and disseminate it. The bedrock of the society has to be intellectual rigour. In her explanation of the work of the technical and publications committee (p10) and in his explanation of how Lighting Research and Technology functions (p13), Sophie Parry and Steve Fotios respectively show the meticulous academic process that underpins publications. Another fundamental layer is the calibre and commitment of the people who write the guidance, organise the events, visit schools, speak

at events and generally spend hours of their spare time informing people about lighting issues. But whether it is a CPD webinar, an international conference, a school workshop or teams competing to produce the most creative result from limited kit in a muddy field, making knowledge accessible and making education enjoyable is at the heart of what the SLL does. It is about inspiration. And it is about finding new ways to communicate in changing times. 'We are aware that those now entering the lighting industry have different preferences for how they acquire knowledge,' says Sophie Parry. 'A pile of books and extensive reading hours is not seen by everyone as the only route to knowledge acquisition.'

JILL ENTWISTLE JILLENTWISTLE @YAHOO.COM

CURRENT SLL LIGHTING GUIDES SLL Lighting Guide 0: Introduction to Light and Lighting (2017) SLL Lighting Guide 1: The Industrial Environment (2018) SLL Lighting Guide 2: Lighting for Healthcare Premises (2019) SLL Lighting Guide 4: Sports Lighting (2023) SLL Lighting Guide 5: Lighting for Education (2011) SLL Lighting Guide 6: The Exterior Environment (2016) SLL Lighting Guide 7: Office Lighting (2023) SLL Lighting Guide 8: Lighting for Museums and Galleries (2021) SLL Lighting Guide 9: Lighting for Communal Residential Buildings (2022) SLL Lighting Guide 10: Daylighting – a guide for designers (2014) SLL Lighting Guide 11: Surface Reflectance and Colour (2001) SLL Lighting Guide 12: Emergency Lighting (2022) SLL Lighting Guide 13: Places of Worship (2018) SLL Lighting Guide 14: Control of Electric Lighting (2023) SLL Lighting Guide 15: Transport Buildings (2017) SLL Lighting Guide 16: Lighting for Stairs (2017) SLL Lighting Guide 17: Lighting for Retail Premises (2018) SLL Lighting Guide 18: Lighting for Licensed Premises (2018) SLL Lighting Guide 19: Lighting for Extreme Conditions (2019) SLL Lighting Guide 20: Lighting and Facilities Management (2020) SLL Lighting Guide 21: Protecting the Night-time Environment (2021) SLL Lighting Guide 22: Lighting for Control Rooms (2022) Guide to Limiting Obtrusive Light (2012) Code for Lighting (2022) Commissioning Code L (2018) SLL Lighting Handbook (2018) CIBSE TM66: Creating a Circular Economy in the Lighting Industry (2021) CIBSE TM65.2: Embodied Carbon in Building Services – Lighting (2023)

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November/December 2023

Secretary’s column/Contents

Contents

FROM THE SECRETARY

Twitter: @sll100

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To download LG14: Control of Electric Lighting: www.cibse. org/knowledge-research/ knowledge-portal/lg14control-of-electric-lighting2023 For more details of Light23: www.lightexpo.london/ For the Light2Perform conference programme: www.build2perform.co.uk/ light2perform

Control of Electric Lighting was launched in September. This is the second edition of LG14 following its introduction in 2016. It sets out a logical approach for the professional designer to consider the consultation, design, specification, commissioning and handover of a lighting installation incorporating controls. As other SLL lighting guides, the SLL Code for Lighting and the SLL Lighting Handbook are updated, their section(s) on controls will be revised to align with LG14. On behalf of the SLL I would like thank LG14 author and chair of the SLL technical and publications committee, Sophie Parry, who incidentally offers an interesting insight into the workings of the committee elsewhere in this issue (see p10). We look forward to exhibiting at LiGHT 23 at the Building Design Centre (21-22 November) and Light2Perform 23, alongside our colleagues at CIBSE’s Build2Perform (5-6 December). The final of the SLL Young Lighter 23 will be held at LiGHT23 and the winner will present their winning paper at Light2Perform. We are happy to confirm that the Light2Perform headline sponsor and exhibitor is Tamlite Lighting, and the LIA and Trilux Lighting are also signed up to exhibit. There is room for many others so if you are interested in exhibiting at the event, please do let me know.

EDITORIAL

SECRETARY'S COLUMN

NEWS

A CALCULATED MOVE

RENEWED LAMPS FOR OLD

Kristina Allison and Irene Mazzei explain why the new lighting-specific TM65.2 was needed to calculate embodied carbon in building services

The circular economy is a familiar concept in heritage lighting, according to Chris Dicks and Bruce Kirk

OF KNOWLEDGE 10 BODY The technical and publications committee is the SLL's source of guidance on lighting. T&P chair Sophie Parry provides an insight into how it works

RISERS 13 EARLY Editor in chief Steve Fotios outlines the reason for a special issue of LR&T which focuses on younger researchers

ON THE STREET 14 WORDS Iain Carlile singles out two recently published LR&T papers on different aspects of road lighting

SHIFT 15 RED Dr Jemima Unwin Teji selects her Top 5 research papers on red light and near infrared radiation in buildings

16 EVENTS

COVER: Central Library of Esfahan Municipality, Iran, lighting design by Behin Lighting Company, winner of a 2023 IALD Award of Excellence

BRENDAN KEELY BKEELY @CIBSE.ORG

Negar Sedighi

If you attended Light Night Leeds then I hope you had as good a time as I did. Many buildings in Leeds city centre were illuminated for two nights in October, including Leeds Minster, lit by the SLL in the style of Pockets of Light (see p4). PoL was an initiative of former SLL president and longstanding, respected member of the society, Liz Peck. A Leeds-based lighting designer she sadly passed away early in 2021. All of the SLL volunteer members were outstanding: those who visited the schools and delivered lighting workshops, those who created the schemes to realise the designs of the pupils and students, those who contacted suppliers asking for equipment and those who organised the onsite activities at Leeds Minster. And so were the brilliant suppliers of equipment who answered the call to loan so many products to light the minster. A special mention goes to David Battersby, Thomas Bray, Elizabeth Cooper, Ana Davydchik, Ed Davenport, Fiona Fanning, Simon Fisher, Jake Hardcastle, Dan Lister, Stephen Redhead, Steve Ripley and Helen Wright, and to suppliers Atrium, F-Mark, Gamma Illumination and Sigma. A review of the event by the brilliant David Battersby, who led the project, will be included in the January/February 2024 edition of SLL Light Lines. SLL Ready Steady Light, which took place in association with Rose Bruford College and the IALD in mid-October, was also a great success. All team places were snapped up prior to the event and the result was a very tight competition. Arup won the Technical Award while Xavio Design won both the Artistic and Peer Awards. A big thank you to the judges: for the SLL Technical Award, Andrew Bissell, SLL immediate past president, and Juan Ferrari and Kael Gillam, director and principle lighting designer respectively at Hoare Lea, and for the Artistic Award, Emma Cogswell, Beatrice Bertolini of Equation Lighting, both of the IALD, and Sofia Alexiadou and Ben Radcliffe of Rose Bruford. A special mention goes to Daniel Paget, project lead at RBC, and Ryan Dunnet, RBC's project technical manager. A full write up of Ready Steady Light will also be included in the January/February 2024 edition of Light Lines. The rewrite of SLL Lighting Guide 14:

News

November/December 2023

THE LATEST NEWS AND STORIES

News SLL SUPPORTS LEADING LIGHT FESTIVAL WITH SCHOOLS PROJECT The winning designs from Society of Light and Lighting workshops at two of the city's schools were used to light Leeds Minster (right) as part of Light Night Leeds last month. The event is the UK’s largest annual arts and light festival, held on 12-13 October. The SLL contribution was part of the Liz Peck Legacy. Earlier this year SLL volunteer members visited pupils at the city's Alder Tree Primary and students at Leeds West Academy to deliver lighting workshops. At the end of the sessions pupils and students were asked to sketch designs for Leeds Minster on the themes of cultural diversity, religion, music and the environment. For the festival, these designs illuminated the facade around the Minster, brought to life by SLL members. 'The diversity of designs submitted by the students made it difficult for the team to narrow down the entries used for the final schemes,' said David Battersby, SLL representative and CIBSE committee member for the Yorkshire region, and instrumental in coordinating the event. 'The team was very impressed, with some of the submissions being really thought-provoking.' Light Night Leeds is an annual free multi-arts and light festival that takes over Leeds City Centre for two nights in October. Starting in 2005, the event has grown year on year and in 2019 was enjoyed by around 150,000 local, national and international visitors. A more detailed report of the event will appear in the January/February 2024 issue of Light Lines www.lightnightleeds.co.uk

WORTH DOING WELL A recent study in Building and Environment links WELL Certification with improved worker productivity, health and creativity. Employee satisfaction with a range of different building elements, including lighting, is significantly improved in WELL Certified offices compared to non-WELL Certified workplaces, according to the largest peer-reviewed study to date. Respondents in WELL offices were 18 per cent more satisfied with access to sunlight, 16 per cent more satisfied with a connection to the outdoor environment and 12 per cent more satisfied with lighting. In all, levels of satisfaction with 20 of 23 aspects related to the physical environment were significantly higher in WELL Certified offices, said the study. Titled 'The potential of highperformance workplaces for boosting worker productivity, health and creativity: A comparison between WELL and non-WELL certified environments', the study examined occupant data from the Asia-Pacific region, including New Zealand, Australia and Hong Kong. To see the study in full, go to: www. sciencedirect.com/science/article/pii/ S0360132323007357

NEW SLL TOOL SCOOPS DOUBLE GREEN AWARD ON THE LIGHTER SIDE… Coloured lighting can be controversial but rarely does the hooha have anything to do with football. So... basically fans of Southampton FC want to know why the lighting on one of the city's bridges, the Itchen Bridge, is blue. Which happens to be the colours of arch rival Portsmouth, while their own strip is red and white. Southampton taxi driver Perry McMillan is leading the charge for change and has appealed to a medieval institution, the Court Leet, accustomed to dealing with local, non-criminal spats. So far he's

not having any truck with the official explanation. Apparently original design proposals for the bridge included red LED finials and strip arrays on each column. But, following consultation with local port and aviation authorities, the colour was considered not acceptable, and so blue light it was.

TM65.2, the lighting version of CIBSE’s Technical Memorandum 65 for embodied carbon in products, has won both Platinum and Green in the lighting category of this year's Build Back Better Awards. Complementing TM66, the CIBSE standard for measuring the circularity of a luminaire, the newly released TM65.2 Embodied Carbon in Lighting Equipment makes it easier and quicker to measure embodied carbon in lighting equipment. It includes a web-based calculator tool. www.buildbackbetterawards.com/tm652-embodied-carbon-in-lighting

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�

Circular economy

LED Flex

November/December 2023

Grand Hyatt, Kuwait: TM65.2 includes more comprehensive guidelines so that the calculation better captures the complexity of lighting products

A CALCULATED MOVE Kristina Allison and Irene Mazzei explain why a lightingspecific version of TM65 – the new TM65.2 – was needed to calculate embodied carbon in building services he conversation around sustainability, embodied carbon and the circular economy in recent years, and even months, has accelerated beyond belief. You don’t have to roll the clock back too far to when it was commonplace for specifiers of lighting equipment to recommend luminaires with halogen or metal halide light sources. And only this year the final phase-out of linear fluorescent lamps in the UK and Europe has begun. So now the lighting industry is in a different, and arguably healthier, place due to muchneeded changes in legislation. It is now in an exciting position and, as we have seen with the release of CIBSE SLL's TM66: Creating a Circular Economy in the Lighting Industry in 2021, the publication is leading that conversation in building services. This conversation continues to develop with the

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recent release of TM65.2: Embodied Carbon in Building Services – Lighting. The original version of TM65: Embodied Carbon in Building Services (the 'parent' document), and accompanying carbon calculator, is an already widely accepted methodology for calculating carbon dioxide equivalent (C02e) in building services equipment – without having to submit products for full Life Cycle Assessments (LCAs), a process that is both lengthy and expensive. As well as offering a route to evaluating and understanding the amount of embodied carbon the materials of a product have, the TM65 methodology can even be used as a tool for product development during its design phase due to the fast turnaround nature of the process. Lighting manufacturers have proved to be

very responsive to industry demands for this data and the 18 case studies within the TM65.2 document demonstrate this point. This methodology enables material data, including manufacturing process data and others, to put a C02e value on lighting equipment. And the more data that becomes available the more ‘environmentally aware’ the decisions made by lighting designers and specifiers will be when incorporating lighting equipment into projects. Moving forward, we hope that the tool will both enable and inspire change from all sectors while the nation looks for economically viable ways to embrace the pathway towards sustainability.

WHY A LIGHTING VERSION OF TM65 WAS NEEDED We were finding that manufacturers of lighting equipment were so keen to calculate the embodied carbon within their products that they were using the parent document and the earlier version of the carbon calculator. Although this was a good place to start, it

Circular economy

showed that the process wasn’t created for this and as a result lighting equipment was showing higher values of C02e than was actually the case. This was largely because the materials found in lighting equipment were not in the tool. This potentially led to similar materials being used that weren’t actually similar at all but nevertheless became a substitute for the calculation. Now we are finding that the results of assessments using the new TM65.2 approach are closer to those found using a full LCA.

THE DIFFERENCE BETWEEN THE PARENT TM65 DOCUMENT AND TM65.2 Basically, there is no difference in the core methodology. TM65.2 simply tries to make the calculation process much easier and clearer for the lighting industry. To achieve this, less importance was given to some generic features that characterise the built environment (such as information on refrigerant charge and leakage) while those features that are more relevant for the impact associated with lighting products were highlighted and made clearer for users.

CHANGES TO THE CARBON CALCULATOR With these objectives in mind, TM65.2 includes more comprehensive guidelines on how to carry out the calculation to better capture the complexity of lighting products, without compromising on the simplicity of the TM65 approach. This was possible also thanks to the involvement of several lighting manufacturers, who were very helpful in sharing valuable information on the material content of their products and allowed the authors to build a list of new embodied carbon coefficients to be added to the TM65 database.

'TM65.2 simply tries to make the calculation process easier and clearer for the lighting industry'

November/December 2023

For example, the embodied carbon coefficients for aluminium from 100 per cent recycled and 100 per cent virgin sources have been added to the aluminium coefficients already present in the database, and indications on how to account for materials that have intermediate recycled aluminium content. However, due to data availability, it was not always possible to find exact matches for material coefficients. To solve this issue, guidelines on what to do with components and materials that are not included in the database were also added, such as indications on how to choose alternative materials. Another important additional feature is the inclusion of clear indications regarding what is needed in the calculation to represent a luminaire, and guidelines on how to account for external/integral light sources, control gear and other auxiliary components.

THE DIFFERENCE THE CHANGES HAVE MADE The inclusion of more specific rules regarding the calculation of embodied carbon in luminaires allows for a higher level of consistency among products made by different manufacturers. This is of great importance because it allows for more meaningful comparisons and a higher degree of harmonisation in the industry. In fact, one of the aims was to make sure that the methodology could be universally applied in the same, consistent way, with less room for subjective choices by the users carrying out the calculation. On the other hand, the inclusion of more material coefficients will allow for a higher level of accuracy in the embodied carbon values, especially the possibility to select personalised recycled aluminium contents. This will contribute to lowering the embodied carbon of products and make the results more truthful to the real efforts made by the industry to adopt more sustainable actions.

THE DIFFERENCE IT MAKES TO THOSE USING THIS METHODOLOGY The authors believe that these new changes have the potential to attract more users from the lighting industry, thanks to the better accuracy that can now be achieved. Lighting manufacturers will be able to carry out the calculation with clearer guidance and rules, and will see embodied carbon results that

better capture their efforts and care for the environment. Lighting designers and specifiers will be able to inform their choices knowing that the embodied carbon of products was calculated following robust guidelines and, as a consequence, more safely compare products based on their embodied carbon values.

WHO IS IT AIMED AT? The document is suitable for everyone who would like to learn about embodied carbon in lighting equipment, whether that is lighting designers who need an appreciation of the impact of a product, or manufacturers seeking to evaluate the carbon performance of their existing product range. Inside the document we give an example using a decision tree for who should instigate the use of the tool at different stages – for example, if lighting designers would like to incorporate products with low C02e into their specification, they might instigate the calculation assessment. However, the next step is for the manufacturer to gather the data for the materials, their manufacturing processes and locations required for the assessment. The designer won’t have access to all of this data without the manufacturer’s involvement.

FUTURE DEVELOPMENTS There are a number of things that we would like to expand on, and this is touched on within the document. So this is only the first and not the final version. As more reliable material data becomes available, we would like to add this to the carbon calculator so that lighting equipment can be well represented and calculated as fully as possible. Of course, the purpose of this document is to enable a faster method for calculating C02e in lighting equipment, and the intention is not to replicate or replace a full LCA. Kristina Allison, senior lighting designer, AtkinsRéalis, and SLL vice president, was project lead for TM65.2 and project manager for TM66 Dr Irene Mazzei is KTP associate, Stoane Lighting and Edinburgh Napier University, and technical lead for TM65.2

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Circular economy

RENEWED LAMPS FOR OLD The circular economy actually means business as usual for heritage lighting, according to Chris Dicks and Bruce Kirk n May 2023, the SLL held a wellattended CPD at Coco Lighting in Essex, giving members a practical look at how light fittings can be reengineered to TM66 Circular Economy principles, rather than scrapped. One striking example on the bench was a 2m diameter cylindrical opal diffuser, one of several feature lights from the atrium of a large office. Formerly populated with T5 fluorescent lamps, transformation was underway to replace these with bespoke LED linear modules. It wasn’t straightforward; our hosts explained that the positions for the T5 lamps had been carefully defined to ensure a uniform wash around the sides and face of the cylinder. An LED source is very different to a fluorescent tube, posing a particular challenge where an omnidirectional light spread is wanted. The proposed solution had to be engineered to ensure that the desired effect could be achieved. As we stood around the bench looking at this huge piece of engineering, it seemed not only obvious it should be refurbished, but perverse that it might not have been. The quality of the original fitting stood out. After many years of use, the diffuser material showed no signs of heat or UV damage. The client had no desire to change the lighting or aesthetics of the entrance. If you were to scrap it, something new would be needed, to fit just the right space on the ceiling, not require new structural support behind, and give a similar light level. The original lighting was just right for the space, and now benefits from a much-reduced energy bill and no need for difficult lamp changes. While a late 20th-century office is unlikely to be considered a heritage building,

� The Norris Museum in St Ives, Cambridgeshire, was an example of repurposing luminaires elsewhere: rows of small glass shade pendants hung above dark wooden display cases bathed in uncontrolled daylight and, despite a quaint charm, were inadequate for the museum. Instead, a few of the salvaged pendants now light the replica study of the museum’s founder, Herbert Norris

'Even the 1930s electric scheme sought only to light specific areas, emphasising the lighting of people and not the building'

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it may become one in time if it is good enough. What stands out with historic buildings is often the quality of the original build. And this often includes ironmongery, furniture, and the lighting. Ely Cathedral dominates the skyline of the Fens, and later this century will celebrate 1000 years of existence. It remains serving its purpose as a place of worship, yet just like our T5

Circular economy

November/December 2023

� Two huge gasoliers standing either side of the altar at Ely Cathedral were installed in the 19th century and converted to electric lighting in the 1930s. They are now being upgraded from tungsten capsule lamps to miniature LEDs

lighting diffusers needs updating and repair from time to time, to ensure it best meets the demands of our world today. Gas lighting was installed in the mid-19th century, lasting through to the 1930s¹. Little remains of the scheme, other than two huge gasoliers, standing either side of the high altar. First converted to electric lighting in the 1930s scheme, these fittings have seen several alterations to their light sources in the past. They are now being upgraded from tungsten capsule lamps to miniature LEDs in the workshops of Great British Lighting, as part of the current scheme to relight the 11thcentury cathedral. TM66 has a good checklist in Section 9.4 for use when looking at the remanufacture of light fittings. When considering refitting a historic light fixture, heritage conservation principles

'We must not slash the consumption of converted halogen fixtures only to treble the amount of new lighting in the building'

also need to be applied. Or in medical terminology, 'first, do no harm'. We must then pose the following further questions: 1

What is wrong with retaining the status quo? 2 What is the objective of renewing the fitting? Is it electrically unsafe, too bright, too dim, hard to maintain? 3 Is it technically achievable, at an economic cost? 4 What are the risks of transporting it off-site? Could it be worked on in-situ instead? 5 Is the intention to replicate the current lighting effect, or do something different? 6 Will the refurbished fitting retain sufficient original character? New technology may offer energy efficiency, but so too would adding double glazing to stained glass windows. 7 Could new technology introduce new risks to the building, say through the heat from drivers where there previously were none? 8 If a previous intrusive modification has disrupted the original design, can it be reused, minimising the need for further such modifications? 9 What consents will be needed for any modifications? 10 If the fitting is not reused, what will happen to it? Few clients are likely to

want a relic non-functional light fitting on display. When considering an old light fixture, what are we trying to replicate? If it once had gas mantles, the light would have been a slightly different colour tone, perhaps at odds with modern expectations. Glass diffusers with GLS lamps would usually have intensity hot-spots close to the bulbs. Does one replicate this with LEDs or go for a uniform wash? Imperfections can make for charm. Historic England offers some guidance here². Many early electric light fittings were adaptations of gas fixtures, with pipes used for wiring right back through the building. Lighting designers in the 1930s lacked precedent for how to make use of this new technology. One early innovation was simply to invert the arms of chandeliers for better light distribution, since an upward burning flame no longer needed to be accommodated. So, a degree of adaptation of the fitting can be justifiable in a historic context to get the best result from the technology. Back to the Ely Cathedral gasoliers. Once the principle of reuse was agreed, the next step was to have them carefully dismantled and transported for refurbishment. Here, detailed record-keeping by the cathedral archivist was invaluable, with photos on file of the previous disassembly for transport and refurbishment undertaken for the 1990s scheme. Once stripped down and cleaned, a design

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Circular economy

� Restoration of the Ely gasoliers is following the principles of previous adaptations: rather than place lights on the old gas spigots themselves, small LED capsules, using magnetic fixings, will be placed around the circular band beneath, illuminating glass crystals fixed on to the gas outlets in the past

could be developed to integrate new light sources. Following the principles of previous adaptations, rather than place lights on the old gas spigots themselves, small LED capsules, using magnetic fixings, will be placed around the circular band beneath, to illuminate glass crystals fixed on to the gas outlets in the past. At present the work is underway and the gasoliers will be ready to return to the cathedral later this year. Heritage projects come in all sizes and budgets. Retaining elements of lighting can be a cost-effective way to keep character. The Norris Museum in St Ives, Cambridgeshire, was one such example. Totally inadequate for the museum, rows of small glass shade pendant lights hung above dark wooden display cases bathed also in uncontrolled daylight. Nevertheless, it had a quaint charm. Following a successful Heritage Lottery Bid, a full refurbishment was carried out, with new and far superior lighting installed. But we eventually found a home for a few of the salvaged glass pendants, lighting the replica study of the

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museum’s founder Herbert Norris. We picture working with traditional materials such as wood and metal when thinking of worthy historic light fixtures. But what if the building is from the mid-20thcentury and the material palette includes concrete and asbestos? This was the challenge presented at Grade II* Listed Guildford Cathedral, an interwar design completed in 1965. Light fittings, along with most of the interior surfaces, were finished with an asbestos coating but integral to the appearance of the space. So, following careful consideration, the wall sconces, pendants, and external bulkheads were removed from site by appropriate licensed contractors and stripped of asbestos. Only then could they be properly examined and disassembled, and their refurbishment planned. In looking back at these examples, we can see that the reengineering of light fittings is nothing new, and that quality design of a product generally leaves us with something worth saving. TM66 provides a poignant new

emphasis on this, with a focus on the embodied carbon and other climate costs associated with constantly manufacturing from fresh raw materials. By some estimates world copper reserves could run out within the next 30 years³. As for the medieval villagers pulling down redundant castles to use the stones for their houses, it will soon simply be too extravagant to use new metal where existing is readily to hand. But is it enough? As TM66 recognises, daylight is our most efficient light source. For the first 800 years of its existence, beyond its glorious windows Ely Cathedral had just a few candles or pitch-torches, and these would have only been for task lighting. Even the 1930s electric scheme sought only to light specific areas, emphasising the lighting of people and not the building. Yet as slimmer profile light fittings and other technology have become available, there is a temptation to light every last niche and archway, far beyond what could have been imagined for the original build. For meaningful energy savings, we must not slash the consumption of converted halogen fixtures only to treble the amount of new lighting in the building. Just as the extensive outdoor lighting schemes of the past decades are being critically reappraised now for their effect on the night sky and ecology, so too indoor schemes must be carefully considered in terms of what we are lighting, and why. We should recognise there can be beauty in darkness and what we choose not to light too. Chris Dicks MSLL is associate director at CBG Consultants and the regional representative of the Home Counties North West region Bruce Kirk MSLL is director of CBG Light Perceptions

References • 1 A brief history of artificial lighting at Ely Cathedral (ecclesiasticalandheritageworld. co.uk) • 2 Internal Lighting in Historic Buildings, Historic England • 3 TM66, Section 9.3

Inside the SLL

November/December 2023

BODY OF KNOWLEDGE

� Some T&P committee members visiting Cambridge University and King's College Chapel this year. From left to right (back row): Simon Robinson, Nicholas Bukorovic, John Fitzpatrick and Benedict Cadbury. Front row: Helen Loomes, SLL president and guest, and Sophie Parry – 'We try and hold one meeting each year in a location that has an interesting lighting installation'

The SLL’s technical and publications committee is the society’s source of guidance on lighting. T&P chair Sophie Parry provides an insight into how it works LL members will be aware of the extensive library of lighting-related publications that can be downloaded or purchased from the SLL website, and of the lighting-associated content to be found in some CIBSE publications. Currently there are around 40 CIBSE and SLL publications that are wholly or partially about or have relevance to lighting. There are also publications created by other organisations where, through collaborative ventures, the SLL has been a major contributor. Nearly all of these publications are written as

guidance – lighting guides (LGs) – focusing on a particular area. They involve the interpretation of legislation and standards, as well as the author’s own expert experience and ability to design and project manage lighting installations relative to the publication title. CIBSE and the SLL are also now starting to supplement written publications with digital tools where modelling calculation software is not readily available. There are two main variations on this format: the SLL Code for Lighting is a combination of reproduced British Standards for key applications of indoor and outdoor workplace lighting and road lighting, with additional commentary, and copious information on the first principles of lighting physics. Meanwhile the SLL Lighting Handbook, the second exception, is more about application guidance and thus complements the Code for Lighting. Our main target audience is the lighting designer and specifier either at student or practitioner level. There are alternative target audiences that we also cater for. LG20, for instance, covers lighting from the perspective of facilities managers, and was reviewed and

commented on by the CIBSE FM group prior to publication. What the SLL can’t do is act on every suggestion put to us by the membership. The guidance published by CIBSE and the SLL is held in high regard and often cited in project specifications, or even used by expert witnesses as part of arbitration. Therefore we have to write in a certain style and be sure of the relevance and efficacy of new ideas, technologies and solutions before they can be incorporated into a publication. But do you as an SLL member know where all the information, knowledge and writing skills come from in order to produce and maintain these publications? This is the role of the SLL's technical and publications (T&P) committee. Many members may not have heard of it, or if they have, are not sure what it does. If you have ever wondered, this is where we demystify what we do. The committee mainly comprises volunteer SLL members and fellows, supported by a technical secretary, SLL staff and CIBSE Publications. Currently the committee

sll.org.uk

November/December 2023

Inside the SLL

The Society of Light and Lighting

The SLL Code for Lighting

Lighting for the built environment — Lighting Guide 2: Sports lighting

The Society of Light and Lighting

The SLL Code for Lighting

The Society of Light and Lighting

The Society of Light and Lighting is part of the Chartered Institution of Building Services Engineers

� The latest Code for Lighting was published last year and is the flagship publication produced by the T&P committee. Right: LG4 2023

14/11/2022 16:20

membership is made up of 18 volunteer members, 16 of whom are contributing authors with ongoing ownership of their assigned publications. The other two members provide a liaison link with the Building Research Establishment (BRE) and various international standards bodies that are mostly product-centric. The chair, also an active author, is additionally a reporting member to the SLL’s Executive Committee, the SLL Council, and is an SLL representative within the Lighting Liaison Group, which is the interface between the lighting industry and UK government.

THE FIRST STAGE So how do you even begin to write a book about lighting? It all starts with an application by the T&P lead author to CIBSE Publications which involves that person outlining the subject matter and reason for the application. The application is also ‘scored’ against essential/relevant criteria that should be covered in the publication in order to represent the CIBSE values that inform responsible design in the built environment, the most obvious one being decarbonisation. If the application is accepted, then formatting and printing funding is made available and the volunteer research and drafting begins. For the author, there are three essential criteria to fulfil: • Being regarded as an authority on the subject matter and being able to manage your chosen contributors. This

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Lighting Guide 4:

forward to 2022 and it became apparent that LG14 required some updating and so the second edition was published in September 2023.

Sports lighting

THE REVIEW PROCESS

The Society of Light and Lighting

Lighting for the built environment

knowledge is typically obtained from first-hand experience of design and/or project management during the construction phase of related application lighting installations in the built environment. • To be able to research and write your draft publication in a logical and articulate way in MS Word. This phase also involves the sourcing of images to illustrate your draft and, in some cases, obtaining written consent to use images, and also consent to reproduce other publications such as extracts from Bsi or other institutions, so as not to infringe existing copyright laws. • To be able to devote some of your spare time to your writing. The creation of the draft is subject to progress updates at quarterly meetings and, of course, there is the collective committee knowledge and experience at your disposal, should you suddenly suffer from writer's block. Timescales vary, but range from a few months to perhaps two to three years, depending on the complexity of the subject matter. Personally, the most interesting challenge I have encountered is authoring a publication on a lighting subject that has not been covered by CIBSE or SLL before. In fact this was my introduction to the T&P committee when I was asked to create and deliver a draft for the then new Lighting Guide 14: Control of Electric Light back in 2015, with publication of the first edition in 2016. Fast

Now the draft needs to be reviewed and this is where the ‘fresh eyes’ and collective knowledge of the technical and publications committee play an essential role. Members review the draft and make constructive comments and often help source those hard-to-find images and permissions that are still outstanding. The draft is then circulated to the SLL Sustaining Member companies (those organisations that make an annual financial contribution to the SLL upkeep) for further review and comment. After these two levels of review, the lead author considers any comments received and adjusts the draft copy if he or she feels the comments are relevant. The final draft is then submitted to CIBSE Publications where it is professionally proof-read and formatted. The draft is subsequently returned to the lead author with a list of any clarifications required by the proof reader. The final agreed draft is then signed off by the lead author and is made into a downloadable PDF for the SLL website. A number of hard copies are also ordered from the printer and made available to purchase via the SLL website.

'The guidance published by the SLL is held in high regard and often cited in project specifications, or even used by expert witnesses as part of arbitration'

Inside the SLL

November/December 2023

PUBLICATION LAUNCH

when you see your work published. Personally I find that the knowledge gained also benefits my day job as sometimes authoring, and chairing the committee, feels like I’m attending one long continuous CPD event. Our committee meetings are held every three months and post-covid we have adopted the hybrid meeting style. However, we decided in 2022 that we should try and hold at least one meeting each year in a location that also has an interesting lighting installation which we could incorporate in a post-meeting tour. In 2022 we were able to hold one of our meetings at Arup's new office at 80 Charlotte St in London, which included a tour and explanation of the intelligent lighting installation. For 2023 we held our annual ‘awayday’ at King's College, University of Cambridge. Inevitably, these types of meeting have to be a hybrid affair as not every committee member can attend in person, but for those who were able to there

The Society of Light and Lighting

HOW T&P 'We are MEMBERS aware that BENEFIT It can be hard those now work, but authors also entering the to hone lighting industry get their personal have different knowledge on the preferences for subject how they through the research acquire required and it’s immensely satisfying knowledge'

Lighting for the built environment

The Society of Light and Lighting is part of the

The Society of Light and Lighting Chartered Institution of Building Services Engineers

Lighting for the built environment — Lighting Guide 14: Control of electric lighting

Chartered Institution of Building Services Engineers

Lighting for offices

The Society of Light and Lighting

The Society of Light and Lighting is part of the

Lighting Guide 7:

Lighting for the built environment — Lighting Guide 7: Lighting for offices

The publication date needs careful consideration in regard to timing and the launch publicity. The release is usually programmed to coincide with the end of a holiday period, such as September or January, as this is a good time to get the attention of the building services and lighting communities. The launch typically involves a 1500-word article that can be used in SLL Light Lines and other relevant publications, a webinar via the CIBSE Grow Your Knowledge Series, and occasional presentation opportunities at CIBSE/SLL regional, national and international events/conferences. Depending on the subject matter, there may also be press releases in other related building and estates publications.

Lighting Guide 14:

Control of electric lighting

The Society of Light and Lighting

Lighting for the built environment

� LG7, LG14 and (previous page) LG4 on sports lighting have all been been published this year

was a post meeting tour of King's College Chapel which has recently had the lighting updated, project-managed by one of our T&P committee members. We also had current SLL president Helen Loomes join our meeting and tour.

WHAT HAS BEEN PUBLISHED IN 2023 We have been productive this year and have been delivering on our 2022 strategy with the following so far published: • •

• •

•

Lighting Guide 7 (LG7): Office Lighting (updated). Lead author: Simon Robinson BRCGS A Guide to Lighting Best Practice – a British Retail Consortium Brand Reputation Compliance Global Standard/SLL joint publication update for the food processing and production industry. Lead author: Sophie Parry Lighting Guide 4 (LG4): Sports Lighting (updated). Lead author: Mike Simpson CIBSE TM65.2 Embodied Carbon in Building Services: Lighting (handbook and digital tool). Project lead: Kristina Allison Lighting Guide 14 (LG14): Control of Electric Lighting (updated). Lead author: Sophie Parry

LOOKING FORWARD We can’t and don’t assume as purveyors of knowledge that our delivery model is perfect. We are aware of, and take account in a measured way, the rapid changes in the lighting

industry and requirements for the built environment, particularly due to the adoption of LED lighting, lighting quality and the contribution lighting products and installations can make towards net zero outcomes. We are also aware that those now entering the lighting industry have different preferences for how they acquire knowledge. A pile of books and extensive reading hours is not seen by everyone as the only route to knowledge acquisition. T&P also provides free-to-download Fact Files which cover a lighting-related subject in just a few pages. Personally, I am also keen to look at creating some short videos with similar content to the Fact Files. I am also keen on the further development of appropriate digital tools where nothing else exists in the market, as not everyone is prepared to or has the time to do calculations by hand anymore. And finally, there are ongoing discussions with CIBSE publications about media creation methods and cloud computing to host all the drafts and associated information. This will not only make digital document management and creation more dynamic but also make future periodic updates and maintenance easier. Sophie Parry, FSLL, is a chartered engineer and head of the Trilux UK Akademie. She is chair of the SLL’s technical and publications committee

sll.org.uk

November/December 2023

EARLY RISERS Editor in chief Steve Fotios outlines the reason for a special issue of LR&T which focuses on younger researchers embers of the editorial board of Lighting Research and Technology (LR&T) are carefully chosen. LR&T is a peer-reviewed research journal, so we need board members with good experience of research and publication. Light and lighting impacts not just on human vision and visual perception, but also on a huge range of other applications including health and wellbeing, industrial processes, plants and animals, and energy efficiency; the board members must be able to reflect this same diversity of interests. It's also essential that the information published in LR&T is accessible to lighting practitioners, so we need members with good experience of lighting design and application, as well as those with knowledge of lighting technology and new scientific and technological developments. In addition to experience, involvement in an editorial board calls for people who can devote their time, particularly in the case of those who act as editors. These requirements frequently mean board

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Research

members are at later stages in their careers, often retired from paid employment. But limiting the editorial board to such people means it may not consider the needs of researchers at earlier stages in their careers. To address this, in 2021 we sought to recruit two new members to the LR&T editorial board – Eleonora Brembilla (top left) of Delft University of Technology, and Kynthia Chamilothori (top right) of Eindhoven University of Technology. They were early career researchers, having completed their PhD studies in 2018 and 2019 respectively, yet despite that early career status, both stood out to us as exceptional researchers with a good record of publication. Having joined the board, Eleonora and Kynthia were immediately asked to act as guest editors for a special issue of LR&T, aiming to highlight the work of early career researchers in lighting. That resulting publication (Vol 55, Issue 7&8), posted in November 2023, is thus essentially research from PhD students. The 10 articles in this issue include research concerning urban lighting, daylighting, nonimage-forming (NIF) effects of lighting, and eye safety when using virtual reality displays. In their editorial, Kynthia and Eleonora highlight the contribution of reviewers to articles published in research journals: 'Reviewers work in the shadow, unpaid and (most often) unacknowledged, to guarantee that published papers are of the highest quality, rigour and clarity,' they say. We certainly endorse that statement and would like to take this opportunity to express our heartfelt thanks to everyone who undertakes the task of reviewing for LR&T. Reviewers are, of course, completely anonymous, and have to remain so, but they are vital to the work of the editorial team and critical to ensuring the ongoing technical excellence of the journal. We would also like to highlight the effort put in by Kynthia and Eleonora as guest editors, and

acknowledge the ongoing work and dedication of all the associate editors. As they know all too well, the editorial role demands much more time than one might anticipate until taking on that responsibility. A first task is to seek reviewers, and in common with other journals LR&T aims to commission two good reviews for each article. This means searching for subject specialists who are able, at that moment, to read and offer constructive criticism of the submitted work. Good subject specialists tend to be busy people so they are not always able to agree to reviewing submitted work. The editorial role therefore demands persistence. On receipt of reviews, the editor then considers the comments that have been raised (which may reflect conflicting opinions of the work), and makes a recommendation on acceptance, rejection or revision. When a manuscript is accepted, the editor is required to read it carefully to ensure journal requirements for language and formatting are met, to provide feedback and guidance to the authors to assist them with making any necessary improvements, and finally to check the proof copy. But although hard work, the editorial role is also a rewarding one, bringing the satisfaction of supporting other researchers and contributing to maintaining a high standard of research in light and lighting. We would therefore like to say thanks to Eleonora and Kynthia not only for joining the editorial board but also for editing the special issue, which is themed as Early Career Researchers in Lighting. Without their hard work this special issue could not have been published. This is also a good opportunity to mention that the LR&T editorial board would be pleased to hear from other researchers interested in becoming more involved with the journal. We would like to hear from people with a good record of publications in peer review journals, so that they are aware of the requirements of publication, and particularly those who can offer experience in subject areas not already covered by the existing editorial board members. We would also like to hear from anyone with a suggested topic for a special issue of the journal, or with ideas for initiatives that would help LR&T become even more relevant for lighting researchers and practitioners. For further information, please contact the chair, Teresa Goodman (teresa.goodman@npl. co.uk) or the editor in chief, Steve Fotios (steve.fotios@sheffield.ac.uk) To read the special issue (Vol 55, issue 7&8): https://journals.sagepub.com/home/LRT

LR&T essentials

November/December 2023

WORDS ON THE STREET Iain Carlile selects two of the most recently published papers in Lighting Research and Technology, each of which focuses on a different aspect of road lighting elloni et al have examined the development of a novel algorithm for street lighting control involving a real-world case study from seven different streets within the Italian city of Perugia. The proposed algorithm does not use full adaptive installation (FAI) systems which continuously monitor traffic, luminance and weather conditions, but instead is based on a number of measured and design values for the applicable streets. Considering the classifications and light level requirements of EN 13201 (parts 1 and 2 respectively), an algorithm was written to allow the street lighting system to be dimmed according to the actual usage of the street itself. The algorithm was written in machine learning tool Pandas (an open-source Python package built on top of NumPY). It was structured in three sections: illuminance and luminance values for each type of street; measured values of illuminance on the streets (allowing the in-situ flux of the lamps to be calculated), and details of the traffic flow measured during a reference period. From this the algorithm compared the values recorded with the design values, and then identified if it was possible to reduce the lighting class of a street by one or two lighting classes (subject to street designation and use). Based on the results a case study was implemented

and the energy usage was then investigated. The preliminary results (which represented 2.3 per cent of the installed street lighting in the city) showed a reduction in energy consumption of more than 64,400kWh/year, reducing both operating cost and carbon-dioxide emitted. The authors note that to apply this algorithm elsewhere does require the traffic flows of the city’s streets to be input into the algorithm. Looking at a different aspect of road lighting, Alshdaifat et al carried out a laboratory experiment investigating road user alertness and the effect of light under varying lighting conditions. Participants were exposed to a lighting condition representing a domestic interior for a period of two hours, before then being exposed for one hour to one of four different lighting conditions. Each of these simulated a different outdoor lighting condition and varied in spectral power distribution and illuminance at the eye in order to give a melanopic equivalent daylight illuminance of <0.5 lux to approximately 10 lux. For the latter phase of the experiment half of the participants walked on a treadmill (representing walking along a street) while the other half remained seated (representing a driving position within a car). Variables recorded included reaction times of participants to an acoustic detection task, melatonin levels derived from

saliva samples, as well as skin temperature and self-reported sleepiness. It was found that the four different lighting conditions did not have a significant effect on any of the variables recorded, confirming the results from a previous study, and suggesting that any alerting effect of road lighting is not significant for driving or walking in the evening. Iain Carlile, FSLL, is a past president of the SLL and a senior associate at dpa lighting consultants

Lighting Research and Technology: OnlineFirst In advance of being published in the print version of Lighting Research and Technology (LR&T), all papers accepted for publishing are available online. SLL members can gain access to these papers via the SLL website (www.sll.org.uk) A new street lighting control algorithm based on forecasted traffic data for electricity consumption reduction E Belloni, C Buratti, L Lunghi and L Martirano The impact of road lighting on road user alertness in the evening A Alshdaifat, NH Moadab and S Fotios

� Illuminance maps for a 100 per cent of the lighting flux for two streets (A new street lighting control algorithm, Belloni et al)

sll.org.uk

November/December 2023

Top five

RED SHIFT Dr Jemima Unwin Teji’s Top 5 research papers on red light and near infrared radiation ver since the discovery of the intrinsically photoreceptive retinal ganglion cells in humans in 2002, research into the potential health effects of light has focused on the blue region of the visible spectrum. In all the excitement, the red end has been forgotten, until recently, when medical research has brought our attention to not only red light, but near infrared (IR), just outside the visible portion of the electromagnetic spectrum. This could be hugely significant, as there’s little red light or IR left in buildings. We have phased out incandescent lamps, introduced low-E glass as standard, and modern heating no longer produces near infrared. The health benefits of red light and the near IR in the built environment is the next (literally) hot topic in lighting. The following top five papers provide intriguing evidence... and are just the tip of the iceberg:

Dr Jemima Unwin Teji is a lecturer at the Bartlett School of the Environment, Energy and Resources Acknowledgements: Prof Glen Jeffery, Dr Annegret Dahlmann-Noor, Prof Peter Raynham and Dr Luke Price have all contributed to discussions of these ideas.

3 A Pilot Study Evaluating the Effects of 670nm Photobiomodulation in Healthy Ageing and Age-Related Macular Degeneration The study compared baseline visual function with performance at one, three, six and 12 months following exposure to light of 670nm at 40mW/sqcm, received by looking at a torch-like tube for two minutes every morning. In healthy ageing, red light improved some aspects of retinal function: eg, a significant improvement (lowering) in scotopic thresholds after daily treatment with red light. The scotopic threshold is the point below which cone cells are nonfunctional, and we need cones to see colour.

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1 Associations of Outdoor Temperature, Bright Sunlight, and Cardiometabolic Traits in Two European Population-Based Cohorts This study of more than 10,000 people in Oxford and Leiden (Netherlands), found a positive association between hours of ambient bright sunlight in the seven days prior to visiting the test centre and metabolic health measured by increased insulin sensitivity and lower triglyceride (type of fat found in blood) levels. This provides evidence to support what most of us already know: sunlight is good for us, and this contains lots of red light and infrared.

4 Sustained and rebound effect of repeated low-level red-light therapy on myopia control: Two-year post-trial follow-up study Looking at low level red light over a two-year period slows myopia progression in children. This study showed how axial length increased more (in myopia, the eyeball becomes longer) in the control group who had no treatment compared to the red-light-group. The children looked at a device emitting red light of 650nm for three minutes, twice a day for five days of the week. Axial length was measured at one, three, six, 12 and 24 months, and compared to the baseline.

2 Weeklong-improved colour contrasts sensitivity after single 670nm exposures associated with enhanced mitochondrial function The mitochondria are the batteries of the vast majority of cells in our bodies. The retina ages faster than other organs, due to the high energy demands of photoreceptors where mitochondrial density is high. This study demonstrates that threeminute long exposure to red light of 670nm in the morning can bring cone-mediated colour contrast thresholds of ageing people (37–70 years) back to levels associated with younger people, and that the effect can last for at least one week. A timely finding given our ageing population.

5 Optical stimulation of mitochondria reduces blood sugar levels This paper demonstrates that red light received via the skin is also important to our health. Red light irradiation of 670nm was applied to participants’ backs for 15 minutes, and 45 minutes later significantly lower blood glucose levels and increased metabolism were found in the test compared to the control group. The research points to red light exposure improving mitochondrial function, reducing blood glucose and increasing metabolic rate. Papers 1 and 5 above are well described at: www.youtube.com/watch?v=6Win49aeh8A

Events

2023

For details of all upcoming webinars, go to: www.cibse.org/societyof-light-and-lighting-sll/sll-events/upcoming-webinars-and-onlinecontent For previously recorded CPD webinars (including regional webinars), go to: https://www.cibse.org/get-involved/societies/society-of-lightand-lighting-sll/sll-events/on-demand-webinars-past-presentations

EVENTS LIGHT 23 (including the final of SLL Young Lighter 23) Date: 21-22 November Venue: Business Design Centre, Islington, London www.lightexpo.london LIGHT2PERFORM (organised by the SLL as part of CIBSE's Build2Perform) Date: 5-6 December Venue: London ExCeL www.sll@cibse.org

2024 LIGHT + BUILDING Date: 3-8 March Venue: Messe Frankfurt https://light-building.messefrankfurt.com IALD ENLIGHTEN EUROPE 24 Date: 21-22 June Location: London www.iald.org

AVAILABLE WEBINARS INCLUDE SIMPLE STEPS TOWARDS SUCCESSFUL AND ENJOYABLE TEAM INTERACTIONS Speaker: David Webster, partner, Centre for Teams LIGHTING CHRIST CHURCH CATHEDRAL, OXFORD Speaker: Mark Sutton-Vane, Sutton Vane Associates Hosted by Chris Dicks Mark Sutton-Vane provides a step-by-step account of how the project was briefed, designed and delivered, from the first concept sketches up to the final focusing and controls commissioning. One of the principal requirements from the client was to keep the cathedral open to the public at all times, requiring a complex phasing programme to be developed for the work. The lighting project also had to be coordinated with other fabric repairs. MERGING WORLDS: LIGHTING IN GAMES, ANIMATION, FILMS AND BEYOND Speaker: Jeremy Vickery, film and gaming production professional Jeremy shares observations from 25 years in the games and film industry and the advent of virtual production which merges the two. He discusses how the use of game engines and architectural LED panels have spawned a new brand in live action filmmaking, shares lessons learned across different lighting disciplines, and how different fields of lighting can enhance each other, and explores common themes that facilitate pleasing visual storytelling using light.