Lighting in Design Q2 2024

Watt-based measures may overlook key aspects of light perception

(CIE), the spectral distribution of light is the density of radiant, luminous, or photon quantities relative to wavelength. This is usually measured in terms of wavelength or frequency. Converting spectral distribution from one variable to another, however, involves complex mathematical transformations, leading to potential misconceptions. The study also examines how light’s spectral distribution changes when expressed in photon terms, revealing significant differences from the spectral power distribution (SPD). “In the photon system, short-wavelength photons have more energy than longer-wavelength ones, altering the distribution peaks. This shift can affect how lighting professionals interpret data, particularly metrics like the blue-to-yellow ratio. Therefore, aligning the units between spectral distribution and action spec tra is essential to avoid misleading conclusions,” says the researcher. Martinsons and his team emphasise that the choice between radiometric and photon units should depend on the nature of the light-induced effects. “Radiometric units are more suitable for thermal phenomena, while photon-based units are better for photobiological reactions, including those mediated by the eye. Using photon-based units in experiments could yield more detailed insights, especially in low-light conditions.” He concludes, “We hope researchers will clear ly specify the system used to ensure accurate data interpretation.”

In lighting research, analysing spectral light distribution is crucial for understanding its interaction with living organisms. “Tradi tionally, this analysis relies on radiometric quantities like watts,” says research engineer Christophe Martinsons. “We believe this approach may need reconsideration. In my study, titled ‘Recon sidering the Spectral Distribution of Light: Do People Perceive Watts or Photons?’, we argue that focusing on the particle nature of light, specifically its interaction at the photon level, might offer more accurate insights into biological effects.” The research highlights that traditional watt-based meas urements may not fully capture the nuances of human light perception. “The spectral distribution, when viewed through the photon system, shows different peak positions and magni tudes compared to the watt-based system,” adds Martinsons. “This suggests that considering light at the photon level might provide a better understanding of its impact on both visual and non-visual systems. Thus, photons may be more relevant than watts in accurately describing human light perception.” According to the Commission Internationale de l’Éclairage

Source: www.inside.lighting.

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Ace LED unveils self-testing emergency LED driver US-based Ace LEDs’ Innovation Lab has introduced self-testing emergency LED drivers with an automated testing process and a power activate feature to streamline emergency lighting main tenance and reduce facility overhead costs.

These drivers conduct a 30-minute test every 30 days and an annual 90-minute test, ensuring compliance with safety regulations. “The Power Activate feature simplifies installation by putting the

battery in sleep mode until the luminaire is installed, eliminating the need for bat tery disconnection during setup,” reports tech website www.edisonreport.com. The sleek, low-profile design allows these drivers to fit seamlessly into var ious linear lighting fixtures, maintaining aesthetic integrity. “They are available in multiple wattage options, including 10, 14, 20, and 30 Watts, with the 30 Watt Class 1 model ideal for warehouse and high-ceiling applications,” adds the web site. These innovations enhance opera tional efficiency by removing the need for manual inspections and reducing costs.

Source: www.aceleds.com

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LiD Q2 - 2024