Askola J, Kärhä P, Baumgartner H, Porrasmaa S, Ikonen E. Effect of adaptive control on the LED street luminaire lifetime and on the lifecycle costs of a lighting installation. Lighting Research and Technology 2021. Epub ahead of print 3 May 2021. DOI: 10.1177/4771535211008179

Features of lighting that can influence people’s behaviours have been identified in an earlier study, along with six scenarios where these could be applied to solve problems with movements through railway stations. The current paper describes the development and testing of novel lighting interventions for three of these scenarios, with two new products controlled by the Internet of Things technology

This article explores the best practices for conducting psychophysical experiments that investigate how colour rendition influences the perception of architectural environments. We offer guidance that covers all stages of research from preliminary development to publication, focusing especially on experiments that investigate qualities such as perceived naturalness, vividness, preference or acceptability

Lighting Research & Technology depends on its reviewers to maintain the high standard of the journal. More generally, much of the authority that the scientific method rightly commands rests on the principle of peer review. Whilst reproducibility of results is generally accepted as a necessary feature of the scientific method, it is evidently the case that the findings from a great many published studies

A range of devices exist that follow the minutiae of our everyday lives. Our heart rates, steps and calories burned can all be logged, whether sleeping, running, cycling, sat at work or simply taking it easy. Once logged, these can be transferred digitally and analysed in a myriad of helpful, or sometimes quite bizarre, charts. Dosimeters or light-logging wearables in the form of electronic watches

Using experimental data from four electric lighting scenarios at King’s College Chapel in Cambridge, we developed an integrated approach to evaluating the overall impression of concert lighting. First, we performed a group analysis based on the aggregated response from the audience, conductor and musician respondents, followed by an overall analysis accounting for all 624 responses. Ordered logistic

There is insufficient current knowledge on the sky luminance patterns under ISO/CIE standard sky types in absolute luminance physical units in cd.m−2 and the resulting horizontal skylight illuminance in lux at the ground level. This paper explains research results and formulae to enable determination of computer applications which help in any location and time to calculate the distribution of luminance

The five articles in the current issue illustrate the broad range of topics associated with outdoor lighting – sky glow, road surface reflectance, road safety and visual performance. They describe the findings of new research so that other researchers can learn of the advance, can criticise, and can plan new hypotheses: gradually, the knowledge base improves.

Functional artificial lighting, when we get it right, is, mostly, unseen and innocuous. With a huge range of products now available at affordable prices, there has never been so much choice. But there is also a worrying lack of guidance regarding how much light is needed and how these products should best be installed. Indeed, there seems to be a belief that ‘brighter is better’ resulting in domestic

We report for the first time the effect of ageing due to adaptive control of lighting on the lifecycle costs of luminaire installations. Two types of LED street luminaire were aged (1) as the luminaire lit for 9 hours and then switched off for 3 hours and (2) under intensive ageing using adaptive control conditions mimicking presence of vehicles, where the luminaires were switched with 30-second interval

Light can impact human health via the visual and non-visual systems originating in the retina of the eye or as optical radiation falling on eye or skin. This paper provides a summary of what is known about these impacts. Topics covered include aspects of lighting likely to cause eyestrain and headaches; increase the risk of falls; induce circadian disruption; enhance sleep; mitigate Alzheimer’s disease

The current pandemic has led us to ask many questions about our society and way of life and the design of the urban landscape. Societal norms that drive urban design are based upon the assumption that people are (relatively) healthy. Covid-19 shows this assumption is false, but buildings and urban spaces do not easily allow the adoption of new behavioural norms such as social distancing. Communal spaces

The importance of daylight in homes is widely understood. The ability of good daylighting to reduce reliance on electric lighting is only the beginning. People equate well daylit spaces with quality and enjoy the variation of natural light and direct sunlight that daylight brings. The key role of light exposure for health is also a major driver for good daylighting, as it is ideal for circadian entrainment

Obstacle detection and facial emotion recognition are two critical visual tasks for pedestrians. In previous studies, the effect of changes in lighting was tested for these as individual tasks, where the task to be performed next in a sequence was known. In natural situations, a pedestrian is required to attend to multiple tasks, perhaps simultaneously, or at least does not know which of several possible

Many applications in various fields require uniform illumination from light sources, for example, in medical imaging in the biophotonics area. In this work, the design and application of an annular light-emitting diode array capable of producing a homogeneous irradiance pattern is presented. As part of the design process, software that allows the simulation of the irradiance pattern as a function of

This study examined the effects of lighting colour on emotional states and the effects of ethnicity on the impact of lighting colours on emotional states, based on the Mehrabian and Russell’s emotional state model measuring pleasure, arousal and dominance. It was hypothesised that there are significant differences in pleasure and arousal among six lighting colours: red, green, blue, yellow, orange

Adequate illumination plays an important part in providing a healthy environment for nursing home patients with dementia. With increasing awareness of non-visual responses to light, new approaches to quantifying illuminance have emerged. In the present study, we assessed the illuminance in nursing home dementia units in terms of melanopic equivalent daylight illuminance, a metric which aims to quantify

Over the last several decades, designers have used digital screens to view images of real and simulated spaces and make critical design decisions. Screen technology has improved during this time, as technologies like OLED have replaced legacy displays (CRT, plasma, and LCD). These new screens provide a higher pixel resolution, luminous output and contrast ratio. Immersive head-mounted displays now

Literature has occasionally reported acute effects of office illuminance on cognitive performance during daytime. The current study was conducted to systematically investigate whether the type of task and level of task difficulty moderate the effect of daytime illuminance on cognitive functioning. Thirty healthy participants were assigned to high (∼1036 lux at eye level; melanopic EDI = 904 lux) vs

In machine vision systems, the objectives to be detected, such as circuit boards, may be composed of many different materials and shapes, which can lead to highlights, shadows and error information in captured images under traditional uniform illumination. A lighting system that generates tailored irradiance in different regions in machine vision is needed. This paper proposes a design method for an

This paper analyses the forecast accuracy of current state-of-the-art, data-driven, spectral sky models. The aim is threefold: (i) to determine the forecast accuracy of existing spectral sky models based on a large dataset of spatially, spectrally and temporally resolved measurements, (ii) to investigate the practical implications of spectral forecast accuracies for the assessment of spectrally selective

Office buildings are building typologies where efficient and optimal use of lighting energy is crucial while providing comfortable visual environments. The purpose of this study is to explore the impact of diverse architectural design alternatives on lighting energy requirements and lighting energy saving possibilities through a case study. In this study, a total of 3888 design alternatives are investigated

Fill light, used to helps cameras capture road traffic conditions at night, can lead to serious visual consequences for drivers. Research on disability glare from LED fill light is scarce and therefore this study explored strategies for controlling disability glare of constant-light LED traffic monitoring fill light. The threshold increment was used as an index to evaluate disability glare. The effective

The present studies examined the feasibility and acute alerting effects of additional in-vehicle lighting within a passenger car. These factors were examined during morning driving (Study 1) and evening driving (Study 2). In a balanced within-subjects design, 37 participants drove a test car two times in the morning or in the evening. The test vehicle was equipped with either a daylight-supplementing

Exposure to daylight has much to offer and should be optimised to maximise its potential. In order to harvest its benefits, any visual discomfort from daylight should be anticipated and minimised. Hence, there is the need to predict discomfort from daylight glare. While more than 20 models for predicting discomfort from daylight glare have been developed, none accurately predict it. The inclusion of

Temporal light modulation (TLM) is a change in the luminous quantity or spectral distribution of light with respect to time of either a light source or a lighting system. These changes arise because of the device or system design, including drivers and control gear, and because of fluctuations in the electrical supply. In former times, families of lighting products all exhibited the same (or approximately

The eagle-eyed among you (particularly those who enjoy reading the print copy of the journal rather than perusing the content online) may have noticed some significant changes to the extent of Lighting Research and Technology over recent years. Long-term readers will know that until 2012 only four issues were published each year, which increased to six per year in 2013 and then eight per year from

With people spending up to 90% of their time in indoor spaces, windows and the visual connection that they afford to the outside, can play an important role in ensuring physical and psychological well-being. This is particularly relevant in urban settings, a substantial part of our lives, whilst still being significantly understudied. What we know from other environments may not translate to cities

The growing awareness of the biological effects of electric light on humans has stimulated ample research. New research has been devoted to lighting solutions that dynamically change their colour to mimic spectral changes of daylight. However, in some situations, the visual properties of light must be preserved, such as when working under standardised lighting conditions to do colour correction in

The traditional square spot of street lamp is not suitable for the lighting requirements of the annular road lighting. In this paper, a lens design method for producing annular spot of high mast lamp is proposed. The method mainly contains three optical surfaces, in which the inner surface collimates the energy of the centre part of the light source, the total internal reflection surface collimates

Light enables us to see and perceive our environment but it also initiates effects beyond vision, such as alertness. Literature describes that at least six factors are relevant for initiating effects beyond vision. The exact relationship between these factors and alertness is not yet fully understood. In the current field study, personal lighting conditions of 62 Dutch office workers (aged 49.7 ± 11

It is expected that the detection of peripheral objects, a key visual task for safe driving, is affected by cognitive distraction, by observer age and by the manner in which action is undertaken following detection. An experiment was conducted to measure these effects, using a fixation cross and peripheral target discs displayed on a screen. The experiment was repeated with young (18–25 years) and

Light-emitting diode is the most dominant lighting technology, and lumen output performance is dependent on junction temperature and operating drive current. An experimental analysis is performed to study the thermal and drive current effect on lumen output, and an empirical model is developed to determine the optimum operating conditions of temperature and drive current so as to obtain a maximum lumen

The main reason lighting control is being applied is to reduce energy consumption. However, there are many more reasons for lighting control to be optimised in buildings. Lighting systems can be controlled to enhance or optimise effects beyond vision. Automatic control of electric lighting systems or daylight systems is one way of adjusting someone’s personal lighting conditions. In addition, it is

My tenure as Chair of the LR&T Editorial Board has coincided with several changes. The number and size of the issues within each LR&T volume has increased and more importantly the quality of the content, as assessed by the Impact Factor, has also increased to well above the critical value of 2. This is due to the authors of papers, but also the work of the LR&T Board, the previous Editor in Chief,

Like a dark cloud is the COVID-19 pandemic dominating the year 2020, but its silver lining may be the renewed awareness regarding

Fotios S, Gibbons R. Road lighting research for drivers and pedestrians: The basis of luminance and illuminance recommendations. Lighting Research and Technology 2018, 50(1): 154–186.

The aim of this paper is to study the reproducibility of measurements in LED lamps. For research purposes as well as for standardized tests, there is a need for measurements to be reproducible so that results can be accurately compared. The knowledge regarding which parameters and test conditions will influence the results is therefore crucial. This paper aims at identifying how changes in supply voltage

Nighttime light emissions are increasing in most countries worldwide, but which types of lighting are responsible for the increase remains unknown. Also unknown is what fraction of outdoor light emissions and associated energy use are due to public light sources (i.e. streetlights) or various types of private light sources (e.g. advertising). Here we show that it is possible to measure the contribution

The general environmental factors that influence fixation distribution as part of pedestrian visual behaviour under natural conditions are unclear. Relative luminance and saliency are considered the parameters for predicting image-based fixation; however, they are not confirmed by evidence from the natural walking scenario. Field experiments using mobile eye-tracking glasses device were conducted on

To meet the increasing demand for mass-produced microalgae, production processes must be optimised and monitored. The herein described optical sensors provide an instantaneous and direct opportunity to monitor biological and biochemical information for microalgae cultivation. Combination of expertise in natural science and engineering, as well as the application of novel data acquisition and analysis

Countless approaches to optimise lighting conditions for indoor and outdoor applications are described in the literature by adaptive dimming schemes or control algorithms. Those methods rely on adapting the emitted flux of individual luminaires in order to adjust lighting conditions to varying circumstances. Complex illumination requirements are tackled by controlling the output of every independent

Lighting-emitting diodes are widely applied in lighting systems, and diffusers are commonly used in systems for indirect illumination. In this paper, a design method of diffuse transmission free-form surface combined with collimation lens array is proposed. Based on the Lambertian characteristics of lighting-emitting diodes and the principle of collimation lenses, a mathematical model of diffuser with

Variable-message signs, which are an important type of traffic sign, have been widely used in traffic control. This study examines the influence of text luminance, text colour and background luminance of variable-message signs on legibility in urban areas under night-time vision. First, the background luminance of variable-message signs in typical urban areas is investigated, tested and classified

Illumination is important for well-being, productivity and safety across several environments, including offices, retail shops and industrial warehouses. Current techniques for setting up lighting require extensive and expert support and need to be repeated if the scene changes. Here we propose the first fully automated light management system which measures lighting in real-time, leveraging an RGBD

Specifications concerning road lighting and photometry of road surfaces were established more than 50 years ago. Road lighting design and road marking visibility were developed for vehicle driving. The observation distance defined by standards corresponds to interurban applications; however, within Europe these areas do not tend to be lit. The objective of the SURFACE project is to propose new geometries

For the design of lighting systems in the built environment, the remarkable diversity of the human population is reduced to a single ‘standard’ observer, which forms the basis for most of the metrics used in product characterisation and specification. Although guidance exists for some specific populations, such as seniors and the low vision population, in most lighting research and most buildings the

This paper discusses the rise of human-centric lighting and its current status in lighting. We summarise the human benefits associated with light and lighting and show that human-centric lighting has sound motivations, despite being tainted by misleading marketing claims. The phrase integrative lighting avoids the hype and encapsulates what lighting aspires to be. Embodied in these concepts are some

A novel high-dynamic range camera-based approach to measure the cumulative daylight dose in historic/conservation spaces has been devised and tested in a real-world setting under normal viewing conditions. The technique derives illuminance from the high-dynamic range-acquired luminance at numerous patches of the wall surfaces visible in the high-dynamic range image. These patches serve as proxy illuminance

Poling RM, Cai M. Calculating luminous flux radiated to a camera lens via high dynamic range photogrammetry. Lighting Research and Technology First Published 19 May 2020, DOI 10.1177/1477153520921442

Connected lighting refers to a system of luminaires and sensors that are networked together and have remote connectivity. By leveraging upon LED lighting, information and communication technologies, connected lighting provides several benefits like sustainable energy savings, remote system health monitoring, data-driven insights and a dense infrastructure for realising new smart building and smart

The current daylighting requirements require a system that can maintain a uniform light output throughout the day while enabling deep and controlled penetration of sunlight. If such a system is simple to manufacture, inexpensive and incorporates no moving parts and maintenance, it can easily fulfil all the daylighting needs. This paper focuses on the development of such a system using laser-cut panels

This article concerns driving after dark. Control of driving speed, being one aspect of the cognitive load of driving, is an important factor which influences visual performance when driving. However, it is not included as a parameter in the widely used models, such as small target visibility and relative visual performance. A driving simulation platform was established to enable investigation of the

Evaluation metrics using climate-based daylight modelling paradigms have become the de-facto standard in work environments but have only limited applicability in residential architecture. Qualities of daylight cited in the architectural design literature, such as daily and seasonal availability of daylight as well as access to direct sunlight, are simulated in detail but are usually overlooked in the

In this paper, a stacked autoencoder network is utilised to realise the signal constellation and transceivers adapted to the dimmable indoor visible light communication system in order to acquire lower symbol error probability. Its decoder parts function as denoising and the equaliser for the proposed multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) visible light

Life-cycle assessment (LCA) has a long history. However, the meaning of LCA has changed through time.

In this paper, we present a post-occupancy study of 326 participants in 10 daylit office buildings in Singapore and correlate the results with climate-based daylighting metrics and electric lighting simulations using calibrated simulation models of the 10 buildings. For the first time, this study tests the climate-based daylighting metrics which are used in building design against their impact on occupant

A camera-aided method of using high dynamic range photogrammetry was developed to calculate luminous flux radiated to the camera lens from an environment or its subareas, with per-pixel contributions from visible light-emitting sources, objects, and reflective surfaces. A series of equations were derived to calculate the luminous flux with valid sub-divisibility and additivity. A pilot study was first

A recent paper proposed a more precise approach for investigating the impact of ambient light (daylight versus after dark) on road traffic collisions. The present paper first repeated that analysis of road traffic collisions in the UK to test reproducibility; it then extended the analysis to determine whether the greater precision affected the outcome of road traffic collision analyses. Results of

With the recent advances in photobiology research and light-emitting diode technology, considering the circadian effects and the potential health benefits of lighting has attracted much attention. In this work, to achieve a white light-emitting LED cluster with beneficial and tunable circadian effects, a red-green-blue-warm white colour-mixing method based on pulse width modulation has been introduced