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 LL2 2025
IS 20 JANUARY
PUBLISHED BY
The Society of Light and Lighting 91-94 Saffron Hill London EC1N 8QP www.sll.org.uk ISSN 2632-2838
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
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)
FROM THE SECRETARY
For this issue, dedicated mostly to early career professionals, Secretary Brendan Keely hands over his column to Maria Englezou, chair of the SLL's newly formed Early Career Community.
Welcome to a special issue which focuses on the recently established SLL Early Career Community (ECC).
For some time the society has wanted to create a group for younger people, including university students, young graduates and professionals working in any area of lighting, which would enable them to participate and reach out if they would like to discuss anything on lighting.
I know from personal experience that there were many times during my studies when I wished that there was someone I could perhaps get in touch with to ask a particular question about a technical or methodological approach. Based overseas, I also wondered if there were any seminars or courses about lighting subjects that I was missing out on simply through my lack of awareness.
Another key concern for early career professionals is how to connect and network with senior professionals in their fields to pursue collaborations.
The ECC forms part of the Young Engineers Network (YEN), itself part of CIBSE, comprising regional centres that aim to provide a forum and support network for early career professionals. The mission of YEN groups is to create a platform for new thinking and novel approaches to design, to discuss ideas, and also exchange knowledge and experiences.
In addition, it will ensure that young lighting designers engage closely with the SLL at an early stage and get support through their career development.
Whether you're interested in the technical aspects of lighting, lighting technologies, architectural design, or the science behind anything related to lighting, this community is designed to support your professional growth.
On a practical level, the ECC will organise events and online meet-ups to discuss any matters related to light and lighting. Our aim is to connect and learn from each other,
share experiences, and even create future collaborations.
The ECC will also work with other CIBSE YEN groups, thus promoting collaborations between different engineering professions. The main scope is to get involved, share and learn from each other. By joining us, you'll be able to:
• Connect with early career professionals and experienced mentors in lighting
• Participate in discussions, webinars and events focused on industry trends, research developments and lighting technology news
• Collaborate with experts and peers across design and engineering fields
• Enhance your career development through shared knowledge and resources
If you would be interested in joining or contributing to the mission of the SLL Early Career Community group, reach out to us.
Let's shape the future of lighting together.
or
⊳
Dr Maria Englezou is chair of the ECC. An architect, researcher and daylight specialist, she is a former SLL Young Lighter winner
A NEW LEASE OF LIGHT
Two SLL members, Florence Lam and John Aston (pictured, right), have both received CIBSE gold medals for their outstanding contributions and dedication to CIBSE, SLL and the wider building services industry. They were presented with their medals at the 2024 CIBSE President’s Awards Dinner.
Florence Lam, FSLL, began her career at Arup while studying engineering at Cambridge University. She won the SLL Young Lighter of the Year award. She cofounded a dedicated lighting design team at Arup. As its global lighting design leader she set the standards for lighting excellence, and directed crucial research and development.
She has received many accolades, including being named Lighting Designer of the Year at the UK Lighting Design Awards in 2013, the first woman to receive this award. Lam is deeply committed to mentorship and knowledge sharing, and dedicated to fostering innovation in lighting design.
John Aston, FSLL, began his lighting career in 1979 with ECS Energy Conservation Systems, where he was appointed business development manager in 1996. He then became green marketing manager for Philips Lighting UK in 2007, with a remit to engage with both industry bodies and government.
He was SLL president from 2014-15, and chair of the education and membership committee, where he led the society in professional recognition for lighting designers. Always interested in training and education, Aston was a mentor to many, as well as chair of the CIBSE CPD Panel. 'Florence and John have consistently been outstanding ambassadors for our industry, continually raising standards and enhancing the quality of our work,' said Dan Lister, SLL president. 'On a personal level, they have both played pivotal roles in my career development, for which I am eternally grateful.'
ON THE LIGHTER SIDE…
With the best will in the world, the average street lamp is not the most exciting bit of kit. It has a serious role, and it carries it out with an air of utility. So Alex Chinneck's whimsical sculptures are a cheering departure.
Two of his three artworks for office development Assembly Bristol feature traditional-style, metal street lamps tied in knots. They are in a line of his urban interventions, some on a breathtaking scale, that include unzipping building facades or tying up their cracks with giant shoelaces.
The lamps remain practical – though possiby not standard-compliant – as despite their convolutions they light up at night with a warm glow. www.alexchinneck.com/projects
More than 110m solar energy kits – 75 per cent of all solar products sold – have fallen into disrepair in sub-Saharan Africa. However, new research by the University of New South Wales (UNSW) and UK charity SolarAid has identified a good opportunity to repair a majority of these lights.
A 2023 white paper by the two organisations has already shown that nearly 91 per cent of these products are still repairable.
Now their first-ever State of Repair in the Off-Grid Solar Sector report, based on insights gathered from 75 key industry stakeholders, sheds light on both the opportunities and challenges faced by the sector.
The report reveals that while 90 per cent of distributors are already offering some form of repair service, smaller companies still face barriers to entry.
Among the problems are access to affordable spare parts (the biggest challenge), issues with last-mile logistics, training, and product design limitations.
The cost of repair and a need for greater collaboration between manufacturers and distributors is also cited.
'This report shows much promise, but it also unearths some of the real challenges we face in addressing repair as a whole sector,' said Jamie McCloskey, director of programmes and partnerships at SolarAid.
'We firmly believe that if we collectively tackle the barriers ahead of us, repair services can be an overall net benefit to the off-grid solar sector, financially and otherwise.'
Chair Maria Englezou and committee members Jack Worsley and Saurabh Mathure explain why the SLL's new Early Career Community is needed and why they themselves were inspired to join
D
uring my postgraduate studies, and especially while doing my PhD, there were many times that I wished knew someone who could ask for advice about something that I did not fully understand, whether it was technical or methodological. was also never sure if I was missing out on any seminars or courses about lighting subjects because of being in another country or just not getting informed by a related professional body.
I was lucky to have participated at the Daylight Symposium and LumeNET Forum, established by Professor Steve Fotios and Dr Jens Christoffersen, which are workshops for PhD students researching lighting-related subjects. I believe that today, due to technological
advancements, we can connect with people working on similar projects even while living in different parts of the world. This is the main reason I wanted to join SLL ECC: so that could connect with like-minded lighting enthusiasts.
One of my personal goals is to create a professional but also fun online community that anyone who wants to discuss anything on lighting can reach out to. Another goal is to create a mentorship programme where early career people could grow, learn and connect with experienced professionals in lighting.
One of the strongest aspects of the SLL ECC is that it will ensure early career people engage closely with the Society of Light and Lighting at an early stage in their career and get support throughout career development. Looking forward, I am very excited about connecting with other early career people anywhere in the world who are interested in lighting design, engineering, research and industry. I feel that this group will foster connections that enhance knowledge sharing and build bridges of understanding in the lighting sector.
Throughout my career in the lighting industry, from being a young naive apprentice to being a senior/team leader, I always found it difficult to find others with the same passion for lighting that have. always struggled with being young and looked down on by others because of my age and not having enough experience in the industry, especially as it often resulted in my opinions being disregarded when ultimately often the same conclusion was provided by more senior members.
This is my inspiration for providing a knowledge base where others can go for advice that looks beyond age and experience. Anyone, regardless of age, gender, race, or number of years' experience, has the same right to provide knowledge and insight in the lighting industry.
My goal is therefore to help create this knowledge base/support hub for those already in the lighting industry trying to navigate the intricacies of lighting design, and to promote the exciting career opportunities available to the younger audiences who, like me at an early stage, might not be aware of the industry or where to start.
By far the strongest aspect of the SLL ECC is to create a global knowledge-sharing network for those at the early stages in their career to give support and insight into not only the vast intricacies of lighting but the great career opportunities that it can open. What I’m most looking forward to is meeting enthusiastic individuals at any upcoming events, not only to talk through my own experiences in lighting but also to expand my own network and give people someone they feel they can reach out to for any support.
My own career transition from engineering to lighting was ignited by a mentor, who showed me how lighting brings spaces to life. Through the ECC, I hope to influence the next generation of architects, engineers and professionals to understand that lighting is integral to their projects, and to see the impact of considering lighting from the start.
'The
strongest aspect of the SLL ECC is to create a global knowledgesharing network'
Due to this I made it my mission to go above and beyond to learn as much as I could to prove the doubters wrong. I was often on my own with little support, which felt quite isolating, but what did find was that having one or two people who gave you a chance and time really made the difference at moments when it would have been very easy to lose this passion and leave the lighting industry
(a huge shout-out to both Gareth Renninson and Tim Bowes at Whitecroft Lighting who believed in me and were instrumental in giving me the reason to continue).
SAURABH MATHURE: SECRETARY
My main inspiration for joining the SLL ECC is to create broader awareness about lighting as an essential field and to highlight the importance of thoughtful lighting design in every project. Lighting is a unique and often overlooked discipline, yet it has a profound effect on both the functionality and ambience of a space.
My main goal is to provide the same type of guidance that helped me in my early career, offering young professionals insight into the nuances of lighting design. want to help others grasp the balance of form, function and sustainability in lighting, and to share insights on navigating real-world challenges, from quality lighting solutions to creating eco-friendly designs. Another personal goal is to build awareness globally, encouraging students and new professionals to recognise that lighting design has a huge impact and that they can be part of this field. For me, the strongest aspect of the SLL ECC is its potential to build real awareness and provide a supportive environment where young professionals can ask questions and engage with mentors. It connects people who share a passion for lighting, whether they're exploring it for the first time or eager to deepen their knowledge, and it will also create a platform to learn and grow together.
I’m particularly excited about activities that will connect students directly with experienced professionals, offering Q&A sessions, and showcase where they can explore lighting as a career path. There are talented students worldwide who want to pursue lighting but lack clear information or resources – the ECC can bridge this gap. I’m also eager to see students from different cultures bring fresh perspectives into the field, especially on sustainability and design. It’s inspiring to think that together we can nurture a new generation of lighting designers who will approach the field with both curiosity and commitment.
For more details and to learn more about committee members: sllecc@cibse.org
MAKE THE GRADE SOONER
Membership executive Fiona Fanning reveals a major change in the SLL's membership application process which will benefit early career lighters
The application process for MSLL (Member grade) has changed and will be particularly helpful for early career lighters as they will now be able to apply for SLL corporate grades much sooner than before.
Until now, the application was focused on education and experience, or experience only, which has meant that applicants had to have a recognised qualification in lighting or alternatively five years’ experience to apply for Associate Member grade (AMSLL) and 10 years’ experience if they wanted to apply for MSLL grade.
However, it has been recognised that there are many early career lighters who have a great deal of knowledge and experience in lighting but perhaps do not have the requisite number of years, and the changes have been made specifically for them.
The new application is based on the Engineering Council’s UK Standard for Professional Engineering Competence and Commitment (UK-SPEC). This allows lighters in the early stages of their career to apply for MSLL via competencies. The new MSLL application will use four of the fiveUK-SPEC competencies:
• A – Knowledge and understanding
An applicant shall use a combination of general and specialist engineering knowledge and understanding to optimise the application of existing and emerging technologies
• B – Design and problem solving
An applicant shall apply appropriate theoretical and practical methods to the analysis and solution of engineering problems
• D – Communication and interpersonal skills
An applicant shall demonstrate effective communication and interpersonal skills
• E – Personal and professional commitment
An applicant shall demonstrate a personal commitment to professional standards in a safe and environmentally acceptable way, recognising obligations to society and the profession as a whole
Please note that competency C – Management is not included as this would exclude many early career lighters from applying for the new MSLL. There are two ways of responding to the four competencies, either through a report based on competencies or a project report. Both methods provide the applicant with the opportunity of including their skills and experience in lighting.
The new process will be completely online and enable applicants to upload their general details, CV, sponsor’s details, organisation chart and any relevant certificates.
MSLL is now not only more accessible to early career lighters, or those who do not have/do not seek management roles in lighting, but also supports those looking to progress their careers within disciplines linked to lighting. The next phase of amending the application process will be to align AMSLL to the four competencies. This will be available in due course and include feedback from those applying for the new MSLL.
Of course, anyone can still apply for SLL Affiliate grade should they just have an interest in light and lighting and would like to access the SLL’s publications and events.
If you have any questions about the new process or need input regarding your MSLL application please email your request tosll@cibse.org
For more details and to apply:www.cibse.org/sll-join
Within the past couple of months, some of us were compelled to embrace the changes associated with the transition to daylight saving time. Pushing back the clock by an hour during winter may seem a small change, but in reality it can induce a
butterfly effect on our circadian rhythm. What is it about the complexities of the relationship between light and the body clock that leads to our own embodiment of chaos theory?
To begin with, the human body clock operates on an approximate 24-hour cycle. This means that
the cyclical patterns of fluctuations in body temperature, melatonin secretion, rest-activity and sleep are to a large extent predictable and reproducible every 24 hours.
But this is not always the case. The body’s adherence to the 24-hour clock is maintained by the most influential external time-giver: light. Removing this timing cue would allow the circadian rhythm (which is slightly longer than 24 hours) to drift over time. With the spinning Earth inducing seasons and light/dark differences throughout the year, this would offset the body’s natural timings of sleep and wake with the sun’s dark/light cycle.
To add to the matter, in our modern society, which is so heavily fixated on a 9-5 work day, this would prove very challenging if people felt naturally tired and ready for bed at 10am. Therefore light has the power to regulate the body clock and enforce our adherence to the 24-hour day.
However, in the indoor environment, daylight availability is restricted and our exposure to light’s timing cues can be disrupted. In place of daylight, we have inundated workplaces and homes with artificial lighting which does not have the spectral content analogous to daylight and therefore to exert a peak response in our circadian rhythms. By default, this can create a discrepancy between the underlying clocks at work in the body and the external cues they are so used to receiving. As a result, functions in the body that are governed by the circadian rhythm become negatively impacted; we feel sleepy, moody and lack alertness at the right times of the day.
Now let us consider people who are living with dementia. Dementia becomes more prevalent with age, and the ageing eye yellows and contracts, meaning it is more difficult to absorb light of the required parameters for exciting the circadian rhythm. In addition, the ratio of melatonin to cortisol is suppressed as the amplitude of their rhythms are reduced to begin with.
Coupled with the fact that people in this group commonly experience sundowning (a growing sense of agitation at this time of day) and that there may be a bidirectional relationship between cognitive decline and poor sleep, this cohort is extremely susceptible to body clock desynchronisation.
As a result, their wellbeing can become negatively impacted and symptoms may worsen. It is therefore clear that light will play a massive role in aligning the body clock and improving the wellbeing of people living with dementia. Since our population spends around 90 per cent of their time indoors (and likely more for people within care environments), this focus on lighting for wellbeing needs to be inclusive of the indoor environment.
However, one of the main challenges surrounding lighting design for people living with dementia is our self-professed lack of knowledge about their individual responses to lighting. Different pathologies of the disease (Alzheimer’s, frontotemporal, vascular and so on) and different stages of progression may influence the response to light. Additionally, individual-specific factors such as previous lighting history, chronotype, age and gender can weigh-in heavily on this. Aside from visual preferences, people have differing emotional perceptions of lighting due to life experiences and memories. All things considered, it can be extremely overwhelming beginning to design lighting for their wellbeing.
My motivation for the SLL Young Lighter competition therefore stemmed from trying to address our lack of understanding about the response to lighting for people who are living with dementia. The problem statement centres on the fact that there are an abundance of parameters that can affect this response: type of lighting (spectral content, timing, duration, melanopic factor and so on), diagnostic factors, demographic factors, and circadian-related factors such as their rest-activity and sleep-wake cycles. We don’t yet know the extent to which these factors interlink (if at all) and how this may vary on both an individual and group level. Only by collating this information can we begin to piece together the puzzle and mine for relationships between certain parameters. Moreover, generating this data will enable us to get an insight into which parameters have the most importance for improving circadian-related wellbeing for every person. And so naturally, this led to the idea of devising an architecture which makes all of this possible.
First and foremost, there is a requirement for lighting to be
� Luminaire and sensing prototype: featuring tuneable white LEDs, radar sensor and a Bluetooth low energy module
� Simulated scenario: residents in a care home have their activity monitored, with data logged and paired with lighting information. Insights are created through machine learning and changes to the lighting
scalable and dynamic, which means using tunable white, dimmable LEDs. Since we do not yet know the optimum lighting parameters for a person’s circadian rhythm, we need to leave this margin for adaptability.
Secondly, we need to be able to monitor the individual response to lighting using unobtrusive sensing devices that facilitate longitudinal monitoring over multiple seasons/years. For this particular group, it is best they are passively deployed from within their environment as opposed to wearables as they may inadvertently increase agitation.
The third factor involves logging this information via a gateway to a database which also plays host to demographic and diagnostic information. In this manner, all of the contributing parameters influencing a person’s circadian rhythm can be analysed to help us
'After 16 weeks, residents were found to have statistically significant improvements in rest-activity metrics, mood and sense of feeling at home'
understand the relationship between light and wellbeing for this cohort. Over time, with enough data, we can then apply machine learning algorithms to this dataset to uncover the most important contributors.
To date, a fitting has been designed with tuneable LED boards and a central aperture for an unobtrusive radar sensing device. The contents of the fitting are masked behind the diffuser. The sensor is depth-sensing and can monitor the three-dimensional translations of movements in real time. Thus by applying domain knowledge, a person’s rest-activity and sleepwake cycles become easily traceable.
The fitting also has an integrated Bluetooth module which connects all devices in a mesh
network. Both the luminaire data (output intensity, CCT, on/off signals) and the sensor activity metrics are then received by the gateway and accessed on a cloud server. Over time, this data will build up a database with lighting exposure and activity metrics about each care home resident (paired with their diagnostic and demographic information on the client side).
Thus the information that we were once so ‘in the dark about’ has now become accessible.
Imagine this architecture deployed across the globe; with our improved handle on big data combined with increasing computer power, the capacity to impose machine learning algorithms to uncover insights and patterns within these datasets becomes possible.
We would be able to ask questions such as ‘How does length of exposure to cooler lighting impact the number of night-time disturbances of Jane Doe in Room 4?’ and expect an informed answer. Similarly, we can use regression analyses to conduct feature importance, and clustering algorithms to group observed patterns and behaviours. It may even prove valuable to invoke Bayesian models to predict certain sleep behaviours based on the lighting a resident has received.
The architecture design proposed in this article facilitates these insights. Once we understand the relationship between lighting and wellbeing for people living with dementia, we can push instruction out to the light fitting to actuate certain
changes in lighting parameters compatible with their circadian needs.
The justification for this research stems from the fact that dementia to date has no cure. The best we can achieve is an alleviation of people's symptoms in an attempt to improve their wellbeing. By concentrating our resources into research in this area, something as simple as a light fitting becomes a huge support for this cohort. To date, I have conducted some preliminary work by deploying these fittings (with an initial daylightsimulating lighting programme) within a dementia wing in a local care home.
After 16 weeks, residents were found to have statistically significant improvements in rest-activity metrics, mood and sense of feeling at home, with a reduction in social isolation. This luminaire and sensor data is expected to be continuously collected over three years to help grow our database. This will generate findings on the relationship between light and wellbeing so that we can eventually tailor their lighting outputs. The aspiration is that this research will aim to not only support people living with dementia, but also those caring for them. Improving the former’s wellbeing can relieve strain on carers which will reduce staff turnover and sick leave. As a result, this can deliver both a societal and economic impact. By sharing the findings made possible by this research, we invite all researchers in the field to contribute to this analysis and incorporate better lighting design for this cohort in the future.
he winners of the three SLL Ready Steady Light awards represented a good cross section of participants: a student team, a manufacturer's team and an independent lighting designer's team.
Team UCL 2, led by Craig Turner, won the Technical Award, with a design called March on Time. The category was judged by Dan Lister, SLL president and Arup UK lighting practice leader, and Dr Jemima Unwin Teji, lecturer and programme leader: MSc Light and Lighting, University College London.
The Artistic Award, supported by the International Association of Lighting Designers (IALD), was won by Team iGuzzini, led by Giorgio Pierini. The design was called Red Shades of Autumn. Judges for this award were Kevin Rosenstand of 18 Degrees and Beatrice Bertolini of Equation Lighting, both IALD regional coordinators, and Sofia Alexiadou, who is programme director BA creative lighting control and programme director MA light in performance at Rose Bruford College.
The much-coveted Peer Prize, judged by the contestants taking part, went to Team DPA Lighting Consultants 1 with a design called Heart of the Forest.
Ready Steady Light, organised in association with Rose Bruford College and the IALD, is one of the society’s flagship events. The competition aims to provide a space for creativity and play, a return to the basics of design and engineering. It provides an opportunity for students to gain some hands-on experience, experimenting with lighting techniques and working alongside practising lighting professionals.
Teams of lighting designers, manufacturers and students create external lighting installations, using a limited selection of equipment and in only 180 minutes. The teams have to overcome challenges without a budget and within time constraints.
This year’s sponsors were Urbis Schréder and Centre Stage Solutions, and special thanks go to
Kai Jones, Millie Graham and Daniel Fisher who led the organisation of the 2024 event.
'Every year, I am in awe of the creativity and innovation displayed by the teams illuminating Rose Bruford College,' said Stuart Page, dean of RBC. 'I can’t wait for next year’s Ready Steady Light, marking its 30th anniversary. It’s definitely an event I wouldn’t want to miss.'
Each year, the society puts out a call to lighting manufacturers who may wish to donate or loan equipment to Rose Bruford College, supporting their lighting education programme and students, along with future RSL events. Any companies interested in finding out more, please contact the SLL at sll@cibse.org
� March on Time by UCL 2, winner of the Technical Award
� The Artistic Award went to the iGuzzini team for Red Shades of Autumn
� DPA Lighting Consultants 1 won the Peer Prize with Heart of the Forest
2023. After seeing the inspiring photos from the SLL Pockets of Light held as part of the Light Night Leeds event, I began thinking – maybe I can do this at the church in my village, Abbots Langley in Hertfordshire?
At the time, I had no idea of the amount of work and organisation that goes into creating a PoL event: the communication, the coordination, and the determination to make sure it all goes right on the night. But armed with tons of enthusiasm and tenacity wanted to bring PoL out into the community and share ‘lighting’ with the local schools.
had a clear idea of what was needed – a venue, school engagement and equipment – so all that remained was their buy-in to support the event. Fortunately, I have some good contacts given that I live in the area. Connecting with the church was the initial task. Using the beautiful photos of past PoL events, put together a presentation to pitch the idea to the St Lawrence church in Abbots Langley. With them on board, next I needed to get in touch with the local schools.
As you might imagine, schools are busy and my (slightly random) enquiry to come into the school to do a STEM lesson in lighting design for an art, design and/or technology class was a bit of a challenge. So, using my best elevator pitch spoke to each of the school receptionists and got through to the right teachers.
There are three local secondary schools in the area – Parmiter’s School, St Michael’s Catholic High School and Future Academies Watford – and I wanted to give them all the opportunity to be part of this event. Using my powers of persuasion, already prepared promo-
presentation, many calls, emails and visits, all three schools were on board too.
Abbots Langley village is close to the Warner Brothers Studio Tour, also known as the Harry Potter studio experience. They have always been keen to support the local area, which made me think –maybe
'The pupils applied what they had learned about lighting in sketch form. Each of their designs showed fantastic understanding of the lesson'
they might be interested in supporting this Pockets of Light event? Again, armed with my presentation and by now well-practised elevator pitch got through to Warner Brothers which was happy to support the event. And they threw in a surprise bonus –they also offered to give the
examples of how to apply them. The lessons were delivered to GCSE year 10 and year 11 pupils who were very engaged with the lighting equipment laid out on the workshop benches. Having the opportunity to explore the lighting products, what they did and the lighting effects they created was new to them. It was exciting.
Mathew Wright from Martin Architectural joined me for one of the lessons and brought along with him a moving gobo projector – the pupils loved seeing the colourful patterns projected on to the otherwise plain wall. After giving the presentation and some hands-on time with the kit, I then set the pupils a task – to create lighting designs using either coloured paints or pencils on to line drawings of the church facades.
Before the event itself, along with Chris Dicks (regional representative for Home Counties North-West) and Elliot from Ohmega Contractors, we visited the church to inspect the electrical connections for safety. We also did a few mini mock-ups to ensure that things would work as planned on the night.
The day had arrived – and we had until it got dark to set up the equipment before the village gathered at the church to see the wellpublicised event. (I had been putting posters on noticeboards all around the village, the local magazine and village Facebook page for months). And it all went to plan. It was a very enjoyable day setting up and just as it started to get dark people began arriving. The Friends of St Lawrence church supplied hot chocolate, and as the public explored the illuminated surroundings their eyes lit up.
winners tickets to the Harry Potter studio experience. This was all coming together nicely but now I needed support from others in the lighting community.
Lighting manufacturers Architainment, Architectural FX, iGuzzini, Martin Architectural, Tryka Lighting, Thorlux and Urbis were all happy to supply equipment for both the STEM lessons and event. I used my event budget from Warner to buy art equipment, and scheduled lessons with the schools to create the fundamental ingredient – the actual lighting designs for the event.
I prepared a STEM lesson presentation covering the fundamentals of lighting, lighting techniques, materials and textures, and
The designs had to follow a ‘Remembrance’ theme as the event was planned for the night before Remembrance Sunday. The sketched concept designs would be judged based on their theme, and creative, technical and buildability merit. The pupils were able to apply what they had learned about light and lighting in sketch form and each of their designs showed fantastic understanding of the lesson.
Then the hard part, selecting a design to realise for the church facades. There were so many well-considered designs to choose from. This would not be a task to be done alone, and with a team of lighting professionals including Simon Fisher, Helen Loomes, Juan Ferrari, Sean O’Callaghan, Mathew Wright, Ryan Rolph and Scott Pengelly, we eventually selected four designs. It was with their incredible support and coordination that we pulled together the lighting equipment that was needed to realise these designs and organise everything in such a short space of time.
People approached the SLL team (who were wearing hi-vis bibs) to discuss the lighting design and express their appreciation. It was clear that the remembrance theme struck a chord with many of them; we received many wonderful comments, and one lady was close to tears. The atmosphere was one of reflection and curiosity. The church was pleased with the result: ‘It absolutely engaged with the local community, who loved it, and who really appreciated having the opportunity to see the schemes put in place... it once again put the church at the heart of the community.' And of course the schoolteachers and the pupils also came along to see their creations realised and were thrilled with the results.
Kristina Allison is associate environmental, sustainability and net-zero lighting capability lead at WSP, and president-elect of the SLL
A huge thank you to Focus Rigging for its generosity in loaning me the crowd barriers, Abbots Langley Parish Council for its support, Warner Brothers Studios, Ohmega Contractors for ensuring electrical safety, Gobo Plus for kindly cutting the gobo design, and Friends of St Lawrence and St Lawrence church for hosting. And not forgetting the three schools who trusted me to deliver the STEM lessons in lighting design – that just maybe inspired some of the next generation of lighting designers.
� Sophia (top) and Matilda (bottom), years 10 and 11 respectively, product design, Parmiter’s School
� Kenzie, year 11, 3D art, Future Academies Watford
� Isabella, year 10, art, St Michael’s Catholic High School
hether inspired by guttering candle flames, a cosy log fire or maybe a dodgy LED driver, several of the papers in the latest LR&T concern flicker. This is more properly called temporal light modulation, or TLM.
As you may know, the SLL already has a fourpage Factfile (17) concerning temporal lighting artefacts (TLAs) which, as well as flicker, also addresses stroboscopic effects and phantom arrays. Unsurprisingly, the LR&T papers deal with the topic in much greater depth.
Over the years, flicker has grown in significance and I agree with Teresa Goodman’s editorial (she is the associate editor and chair of the LR&T editorial board) that this is due to the fact that LEDs respond almost immediately to changes in the drive current. The most likely and commonest cause is changes in the AC mains supply.
This is compounded by other factors such as pulse width and pulse frequency modulation for dimming/colour changing. Flicker can occur at almost any frequency.
It may be that you, the reader, like most people, are not too affected by flicker. However, around 15 per cent of the population suffer from migraine and
for them the effects of flicker can be debilitating. There is a moving piece in the correspondence section by Naomi J Miller of Pacific Northwest National Laboratory where she lists examples of the more serious side-effects of TLM.
The European Ecodesign Regulation, introduced in September 2021, dealt with two aspects of TLA metrics: flicker and stroboscopic effects. The paper by V Mantela et al, 'Improvement of temporal light artefact effects in commercial LED lamps', is a review of the TLA behaviour of 80 different types of E27-base LED lamps purchased before and after the Ecodesign regulation was put in place.
The visibility of flicker is described by a metric called short-term flicker severity index (Pst, LM). The Ecodesign regulation limits Pst, LM to <1 where 1 is the 50 per cent probability threshold for the flicker visibility for an average observer.
Similar to flicker, the stroboscopic effect has a metric that also describes its visibility to an observer. This is called the stroboscopic visibility measure (Mvs) also known as SVM. The regulation originally limited Mvs to <0.9 and then to <0.4 from September 2024.
Much of the difference in flicker is due to the type of power supply and these are categorised into four
groups in order to more clearly understand and compare the results.
In summary, the stroboscopic effects Mvs are considerably lower with newer lamps. However, there was little change in the flicker Pst and this is most probably due to manufacturers being much more aware of flicker in this type of lamp. It is interesting to contrast the Ecodesign metric of 50 per cent visibility with the much smaller value of 15 per cent of people who can be badly affected.
In the authors’ view, 15 per cent is still very significant, so do we need a much stricter visibility threshold in the regulations?
If you are not involved in photometric research, you may not have come across the technique known as 'lock-in detection'. The paper by C Martinsons and N Picard, 'Untangling light in noisy luminous environments', describes how the TLM footprint of a light source can be used to measure the illuminance from a dim source even under daylight conditions.
Illuminance levels 500,000 times smaller than the background were reliably measured by lock-in detection. Furthermore, using a new type of optical lock-in spectrometer, it becomes possible to retrieve spectral quantities through the TLM of the light source. For example, you can measure the SPD of a light source even in full sunlight. This opens up interesting opportunities to characterise anthropogenic light pollution.
Alan Tulla is a former president of the SLL and principal of the independent consultancy Alan Tulla Lighting
Lighting Research and Technology: OnlineFirst
In advance of being published in the print version of Lighting Research and Technology (LR&T), all papers accepted for publishing are available online. SLL members can gain access to these papers via the SLL website (www.sll.org.uk)
Editorial: Temporal light modulation
Teresa Goodman
Improvement of temporal light artefact effects in commercial
LED lamps
V Mantela, R Nordlund, J Askola, P Karha, P Dekker and E Ikonen
Untangling light in noisy luminous environments
C Martinsons and N Picard
Chiara Carucci selects eco-sensitive schemes
Adopting an ecosystem-based approach in lighting projects is both possible and rewarding, as demonstrated by recent case studies such as the pilot projects for the EU LIFE21 Turtlenest initiative (Light Lines, Sept/Oct 24), and many examples at the 2022 ROLAN conference.
One of the key factors for success is interdisciplinary collaboration, particularly with researchers, which leads to more efficient projects in terms of time and cost. While my Top 5 examples of ecologically sensitive lighting designs don’t specifically address the cascade effects of lighting on ecosystems, they highlight crucial elements like stakeholder collaboration, and thorough context and needs analysis.
Chiara Carucci is principal of Noctua lighting design, and winner of a DarkSky Award in 2024
Newport Dark Sky Masterplan
The Newport Dark Sky Masterplan in County Mayo, Ireland, developed by Dark Source in collaboration with Mayo Dark Skies, works to eliminate light pollution while balancing the town's visual, social and environmental goals. In collaboration with the local community, the project aims to protect dark skies and enhance the night-time experience for both people and biodiversity. The first phase, at St Patrick’s Church, reduced nearly two tonnes of CO2e annually, and demonstrates that impactful night-time imagery can be achieved with careful, minimal lighting.
City of London Lighting SPD
The City of London Lighting Supplementary Planning Document by Speirs Major adopts a new approach to minimising lighting's environmental impact, while promoting solutions that harness the social and economic benefits of good design. Aside from brightness zones, curfews, and very clear guidelines, the SPD also includes a ‘Lighting Charter’ that encourages building owners and tenants to voluntarily sign up to many of the initiatives. Engagement and public awareness are key not only to successful projects but also to maintenance and future developments.
Le Musée des Augustins, Toulouse
Le Musée des Augustins in Toulouse, one of France's oldest museums, has a lighting design by Quartiers Lumières that subtly enhances its Gothic facade at night. They were among the first to use gobo projections, recreating historic passageways by highlighting specific brick patterns with black-and-white glass gobos. This technique blends seamlessly into their refined lighting scheme, which respects the building’s heritage while simultaneously adding a storytelling element to the design, demonstrating how light can evoke history in a darker context.
Roger Narboni, Concepto
Not just a project, but a homage to Roger Narboni and Concepto studio. They have been working on trame noir (dark plan) from the beginning, contributing – among other well-thought-out, comprehensive projects and strategies – to Lille’s dark infrastructure to protect biodiversity. France is one of the first countries to have applied the Strategy for the Conservation of Biodiversity (COP15), and they aim to reduce light pollution by 50 per cent by 2030, guided by a national regulation on light pollution.
At the Ann and Jim Goodnight Museum Park, part of the North Carolina Museum of Art, Civitas landscape firm applied the principle that even, low-intensity lighting improves visibility. Lighting designer Linnaea Tillett interpreted this concept by placing shielded fixtures at regular intervals along pathways to minimise glare. In the 'wave garden', focusable luminaires softly illuminate benches and lawns, creating warm, inviting spaces for gatherings. This subtle lighting strategy enhances the park’s 65 hectares without overwhelming its natural beauty or creating stark contrasts.
Ann and Jim Goodnight Museum Park, North Carolina
Events 2025
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+INTELLIGENT BUILDING MIDDLE EAST
Date: 14-16 January
Venue: Dubai World Trade Center https://light-middle-east.ae.messefrankfurt.com
WORKSPACE DESIGN SHOW
Date: 26-27 February
Venue: Business Design Centre, London N1 https://workspaceshow.co.uk/
ILLUMINATING THE FUTURE: BALANCING LIGHT AND DARK NIGHTSCAPES
(Organised by the SLL)
Date: 27 March 2025
Venue: Senate House, University of London www.sll@cibse.org
EUROLUCE
Date: 8-13 April
Venue: Milan Fairgrounds www.salonemilano.it/en/exhibitions/euroluce
DARC AWARDS
Date: 24 April
Venue: Fireworks Factory, Woolwich Works, London SE18 https://darcawards.com/
NET ZERO LIGHTING CONFERENCE
Date: 29 April
Venue: Coin Street Conference Centre, London SE1 www.recolight.co.uk/net-zero-lighting/
LIGHTFAIR 25
Date: 4-8 May
Venue: Las Vegas Convention Center www.iald.org
CIE MID-TERM CONFERENCE
Date: 7-9 July
Location: Vienna https://vienna2025.cie.co.at/
LET DIPLOMA IN LIGHTING DESIGN
For details and registration: www.lightingeducationtrust.org
