As an IES Member, I look forward to each issue of LD+A and read them with great interest as they are often very informative. To my surprise, the Research article (May 2019, p. 76) has an error which should be corrected.

During the 20th century, many people migrated to cities for employment and economic opportunities, abandoning farming and natural landscapes so their direct connection to the countryside and nature was lost. This process continues to this day with unprecedented urban growth, in fact, it’s estimated 68% of the world population will live in urban areas by 2050. Due to the evolutionary disposition of humans, when people live in an urban habitat they will still seek to restore their lost relationship with plants and the natural world.

Architectural Lighting Design (ALD) has never been a standalone professional discipline. Rather, it has existed as the combination of art and the science of light. Today, third generation lighting professionals are already creatively intertwining these fields, and the acceleration in scientific, technological and societal studies has only increased the need for reliable multidisciplinary information. Therefore, a thorough re-examination of all aspects of ALD and how it relates to those particular changes is an urgent necessity. Further research is required to develop a new body of knowledge about ALD so that lighting professionals can improve their expertise in the field and receive better remuneration for their complex work. In the near future, we should be aiming for professional recognition as experts and join other recognised professions such as: architects, doctors, dentists, lawyers, engineers etc. While lighting designers (LD) need to constantly update and reexamine their knowledge, they face two dilemmas. First, WHERE should they search to obtain useful information on lighting in related fields? And secondly, HOW should they successfully evaluate the viability of this information in a time of “Google-isation”, Wikipedia, “lobbying” and data manipulation.

Urban environments have become significantly brighter and more illuminated, and cities now consider media architecture and non-static, self-luminous LED displays an essential element of their strategy to attract residents, visitors, and tourists in the hours after dark. Unfortunately, most often, they are not designed with care, consideration, and awareness, nor do they support the visual wellbeing and circadian rhythms of humans. They also increase light pollution which has an adverse effect on the environment. The aim of this study was to estimate the scale of the negative impact of 28 non-static, self-luminous LED shop window displays within a real-life city context along the main shopping street Banhofstrasse in Zurich, Switzerland. An experimental field measurement survey investigation was performed to identify visual luminance with commonly available tools such as a luminance meter and a digital reflex camera for luminance photography. Moreover, the most important global approaches to reduce light pollution were evaluated in the form of existing guidelines, technical standards, and laws, all of which should be considered when specifying illuminated digital advertisements. A literature review and survey results both confirmed the extent of the problem and highlighted, too, the need to better measure, apply, and manage this new technology. The authors’ proposal for improvements involve practical recommendations for the design and implementation of future projects which can positively guide and direct this growing trend.

During the twentieth century, lighting designers would commonly use incandescent light sources for residential homes as they provided a visual comfort, with high quality colour rendering properties, along with relaxing ambient atmosphere. Unfortunately, it’s now difficult to buy incandescent light sources because they have been banned in many countries (https://bit.ly/2GwN2Wv). This article addresses some of the challenges in regards to health, brought about by the changeover to new LEDs and other related technologies, and tries to offer some context on how to keep up with these rapid transformations. While we know it’s necessary to limit blue-rich light at night (as it prevents melatonin production and impaires nocturnal sleep), and that it’s important to maximise exposure to the blue wavelength of light in the morning (to trigger circadian timing, increase alertness), there are other issues that are misunderstood and often ignored. This includes flicker from LEDs and electromagnetic fields (EMFs), which can be produced by smart home lighting technology.

We live in challenging times, and one could even claim we’re experiencing a revolution in lighting with LED technology taking over the world. Part of this rapid change involves a concept called Human Centric Lighting (HCL). In Frankfurt this year, during Light+Building, it was the buzzword, with nearly every second manufacturer’s stand claiming they had figured out the special formula necessary to create perfect HCL illumination. But how can such claims be legitimate when we know so little about the full and complex impact of artificial lighting on human biology, let alone how to responsibly apply this new approach?

Ever since we began illuminating the exterior of the slender skyscrapers built during the of 20s and 30s in XX century, urban lighting has been considered a way to beautify cities, and make them more visually prominent and safe. At that time, we knew so little about the impact of lighting on humans, flora and fauna, so it never occurred to lighting designers then, that their actions would have harmful consequences. In those days, it was all about demonstrating the power of light and technology at night. Thankfully, in the last two decades in particular, professional lighting designers have recognised they have a responsibility and moral obligation to use lighting with far more care, caution and restraint. This has been largely driven by the vast research that’s accumulated in different fields involving astronomy, biology, medicine, ecology etc. – all of which confirms that artificial light at night has far-reaching negative impacts that go far beyond what we could have first anticipated. Today, we are not only accountable for designing illuminating urban elements such as buildings, squares, landmarks, and parks etc. so they look visually pleasing and are energy efficient. Most importantly, our designs must be as safe, sustainable, and as responsible as possible. It’s imperative we acknowledge what’s at stake because the general public is watching us, demanding improved, healthier lighting.

Ornamental plants are often used in indoor environments as part of biophilic design to improve the health and wellbeing of occupants, and to support sustainable, green architecture. Unfortunately, many plants do not thrive and need to be continuously replaced, which is economically unsustainable. The wavelengths and spectrum ratio of commonly used light sources such as light emitting diode (LED), and the lack of an appropriate light dark cycle (photoperiod), appear to be crucial influencing factors. Therefore, this study focuses on determining the optimal action spectrum of LEDs for visually and biologically effective illumination for plants, and humans as end users. This practice-based research study applies critical analysis of literature, photographic evaluation of the appearance of plants under various LED lighting in the form of a visual assessment questionnaire-based survey, and provides various measurements that record the properties of light including correlated color temperature (CCT), color rendering index (CRI), spectral power distribution (SPD), peak light wavelength (λP), photosynthetic photon flux density (PPFD) and daily light integrals (DLI). Research confirms the LED lighting used for horticultural food production cannot be applied to ornamental indoor plants due to fundamental differences in purpose. Such illumination provides fast growth for market consumption and usually makes plants appear unnatural, whereas ornamental plants in an indoor environment should grow at an appropriate speed which reduces maintenance costs and they should have a natural appearance. These new findings, supported by evidence and data, can help investors, clients, architects, landscape and lighting designers, as well as luminaire manufacturers, make improved, biophilic-sustainable lighting design choices.

“The struggle for light” is how the Swiss architect Le Corbusier described the history of architecture in 1935. Today, with the skies crowded out by buildings in modern cities, those words should ring in the ears of policymakers and planners. Skyscraper construction is booming. China is the leader, last year completing 88 of the 143 buildings around the world that are taller than 200 metres (see ‘Vertical growth’). As the nation’s urban populations swell, by 2025 it will need to build 10 cities the size of New York, or 5 million buildings, to house people migrating from the countryside. Most of the buildings will be tightly packed towers of flats. These ‘vertical cities’ will look a lot like Hong Kong, one of the world’s densest urban areas, which has 26,000 people packed into each square kilometre.Beyond Asia, even historic European cities such as Frankfurt, Amsterdam and London are now embracing skyscrapers. London’s skyline is set to be transformed by 510 tall structures over the next decade. Middle Eastern cities such as Dubai and Doha are competing to erect ever more showy palaces in the air. But dense, vertical development comes at a huge price. Placing tall buildings close together slashes levels of natural light in and around them. In Asia and Australia, solar ultraviolet radiation can be reduced by up to 90% in shaded ‘urban canyons’. Evidence is emerging of the widespread health effects of chronic low exposure to natural light, from vitamin D deficiency to short-sightedness. And dense, dark cities will be energy-hungry and unsustainable.

Lighting has the power to illuminate and enhance our experience within the built environment. The light that enables people to travel around their neighbourhood or their city; the light which they see themselves and their neighbourhood under. Research into the effects of urban lighting on behaviour, environmental psychology and social interaction is developing at a rapid rate. Yet, despite the affect it has on our daily lives, the practical application of this research is a relatively untapped resource. There has been a persistent trend to use lighting as a tool for urban regeneration and many major urban lighting projects around the country are underway but there is more that can be done on a variety of scales. This book explores the needs and experiences of people at night and how these can be addressed by public lighting. It will give readers the confidence to develop more sophisticated lighting plans and add value to their projects. Case studies provide in-depth analysis of real-life projects and will help the reader to understand lighting designers’ own experiences, including post-installation observations. Written in an accessible style by an array of experts, this is an essential book for practitioners, academics and students alike, that will enable you to put the research in to practice and develop better lighting for better places.