Lighting Research &Technology, Ahead of Print. At temporal light modulation (TLM) frequencies between 80 Hz and 20 000 Hz observers may perceive a series of repeated images called the phantom array effect (PAE) when they move their eyes in large saccades across a modulating light source or across a scene lit by the modulating light source. To date, there is no well-established measure for quantifying PAE visibility, but there is growing awareness of the need for one among design professionals and sensitive populations. This paper documents a new measure, the phantom array visibility measur ..read more

Lighting Research &Technology, Ahead of Print. Investigating the risk of road crashes associated with ambient light is often challenged by bias resulting from confounding effects of other risk factors. The study used the odds ratio and the risk ratio methods to isolate the effect of ambient light from other risk factors. This was possible in this research using the ‘whole-year’ approach adopted in previous research and utilising seasonal variations in ambient light in Cape Town. The analysis was based on crash and ambient light data collected between 2014 and 2018 in Cape Town. A total of ..read more

Lighting Research &Technology, Ahead of Print. The non-image forming effects of light are moderated by various aspects such as dose, spectrum or temporal and spatial patterns. One of them, the spatial distribution of light within the field of view, has been scarcely researched. Although few studies suggest effects on melatonin secretion during night-time, the daytime effects remain unknown. In this project, we investigated the effect of three light directions – from above, below and the side – each illuminating different retinal regions. The luminance and the size of the light source were ..read more

Lighting Research &Technology, Ahead of Print. The introduction of white light-emitting diodes (LEDs) is one of the key innovations that has revolutionized the lighting industry due to its multiple benefits. Despite their advantages, there is a gap in the environmental impact information of the recently developed high-power LED products within the whole lifecycle, which is a key step to achieve sustainable and green development. This life cycle assessment (LCA) is conducted by considering the cradle-to-grave system boundary. The functional units considered are a LED and compact fluorescent ..read more

Lighting Research &Technology, Volume 56, Issue 2, Page 110-112, April 2024 ..read more

Lighting Research &Technology, Volume 56, Issue 2, Page 107-109, April 2024 ..read more

Lighting Research &Technology, Ahead of Print. With increased consumers’ demand for safe and healthy food, LED lighting for photobiology has received wider attention. In order to prolong the preservation time of the post-harvest lettuce, this paper documents a novel light source designed for preservation based on the chlorophyll absorption spectrum. Effects of intermittent exposure (35 μmol m−2 s−1) on sensory quality and chlorophyll content in fresh lettuce were investigated during 3 days storage at 20°C ± 1°C and 60% ± 1% humidity using dark as the control. The results show that the ligh ..read more

Lighting Research &Technology, Ahead of Print. Current New Zealand (New Zealand Building Code), Australian (National Construction Code) and American (International Building Code) building codes include deemed-to-satisfy requirements for a given proportion of a house’s floor area (e.g. 10%) to be in windows. These, plus the current English Building Regulations, also require a proportion of windows to be openable (e.g. one-half or 5% of the floor area). A detailed summary table supported by code extracts is used to trace the evolution of these requirements. Even the architects of antiquity p ..read more

Lighting Research &Technology, Ahead of Print. Light absorbed by sensitive artwork may cause irreversible damage. Optimising the spectral power distribution of light sources to minimise absorbed light can reduce damage while maintaining the colour appearance of the artwork. Previous absorption-minimisation studies used optimisation methods without comparing their performance. Here, three-channel LED-augmented reality projector spectra were optimised for 24 colour samples using a brute-force (BF) and multi-objective genetic algorithm (MOGA). The BF search and MOGA performed similarly in ach ..read more

Lighting Research &Technology, Ahead of Print. One of the promising irradiation modes for plant is dynamic, when parameters change throughout the growing process depending on certain factors. In this work, lettuce plants were illuminated under different LED light sources, including white (2700 K), 30% white (2700 K) + 70% red (660 nm), 15% blue (445 nm) + 85% red (660 nm), 40% blue (445 nm) + 20% red (630 nm) + 40% red (660 nm) and dynamic mode for 35 days to investigate the effects. Photosynthetically active flux density was the same for all lettuce samples during the experiment (210 µmol ..read more