All Things Lighting® Association https://www.allthingslighting.org/ Illuminating the Complicated! Fri, 07 Nov 2025 21:17:52 +0000 en-US hourly 1 https://www.allthingslighting.org/wp-content/uploads/2023/08/cropped-ATLA-favicon2-32x32.jpg All Things Lighting® Association https://www.allthingslighting.org/ 32 32 Illuminate the Future of Light and Well-Being at Canada Light Expo 2025 in Toronto, ON https://www.allthingslighting.org/canada-light-expo-2025/ https://www.allthingslighting.org/canada-light-expo-2025/#respond Fri, 07 Nov 2025 21:17:16 +0000 https://www.allthingslighting.org/?p=5265 FOR IMMEDIATE RELEASE Illuminate the Future of Light and Well-Being at Canada Light Expo 2025 in Toronto, ON November 12 & 13, 2025. On November 13 at 8:15 AM, at the Canada Light Expo, All Things Lighting® Association will host an interactive workshop titled “Unplugged but Illuminated – Finding Balance in a Technological World.” View […]

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]]> https://www.allthingslighting.org/canada-light-expo-2025/feed/ 0 Refinements to the Worthing Relationship – A Quantum Version of Wien’s Displacement Law https://www.allthingslighting.org/refinements-to-the-worthing-relationship-a-quantum-version-of-wiens-displacement-law/ https://www.allthingslighting.org/refinements-to-the-worthing-relationship-a-quantum-version-of-wiens-displacement-law/#respond Wed, 05 Nov 2025 00:00:55 +0000 https://www.allthingslighting.org/?p=5227 Refinements to the Worthing Relationship – A Quantum Version of Wien’s Displacement Law Eric Bretschneider, Ph.D. Abstract Wien’s Displacement Law is a simple equation that allows calculation of the peak wavelength for a black body light source as a function of temperature. However, not all uses of light are based on radiant flux. In particular, […]

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]]> https://www.allthingslighting.org/refinements-to-the-worthing-relationship-a-quantum-version-of-wiens-displacement-law/feed/ 0 Finding the Danger Zone of the Circadian Stimulus Model: A Summary https://www.allthingslighting.org/finding-the-danger-zone-of-the-circadian-stimulus-model-a-summary/ https://www.allthingslighting.org/finding-the-danger-zone-of-the-circadian-stimulus-model-a-summary/#respond Tue, 04 Nov 2025 23:55:01 +0000 https://www.allthingslighting.org/?p=5248 Author: Alexander Willemsen, Degree of Master of Science of Engineering Based on a paper authored by Eric Bretschneider, Ph.D. The Circadian Stimulus (CS) model is one of the most well-known models for quantifying the circadian impact of lighting. One striking feature that separates the model from other contemporary circadian lighting models is its discontinuous action […]

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]]> https://www.allthingslighting.org/finding-the-danger-zone-of-the-circadian-stimulus-model-a-summary/feed/ 0 All Things Lighting Association Wine Reception at the IES Conference in Las Vegas https://www.allthingslighting.org/wine-reception-ies-conference/ https://www.allthingslighting.org/wine-reception-ies-conference/#respond Thu, 23 Oct 2025 16:21:29 +0000 https://www.allthingslighting.org/?p=5204 The post All Things Lighting Association Wine Reception at the IES Conference in Las Vegas appeared first on All Things Lighting® Association.

]]> https://www.allthingslighting.org/wine-reception-ies-conference/feed/ 0 Can Designs and Measurements Based on the Circadian Stimulus Model Stand the Test of Time? https://www.allthingslighting.org/can-designs-and-measurements-based-on-the-circadian-stimulus-model-stand-the-test-of-time/ https://www.allthingslighting.org/can-designs-and-measurements-based-on-the-circadian-stimulus-model-stand-the-test-of-time/#respond Tue, 13 Aug 2024 06:01:18 +0000 https://www.allthingslighting.org/?p=4817 Author: Eric Bretschneider, Ph.D INTRODUCTION When considering the potential circadian impact of lighting, lighting designers have a choice between three different models: melanopic equivalent daylight illuminance, or m-EDI [CIE 2018]; equivalent melanopic lux, or EML [WELL v2]; and circadian light, or CLA [UL 2019]. Both m-EDI and EML have a continuous action spectrum, which means […]

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]]> https://www.allthingslighting.org/can-designs-and-measurements-based-on-the-circadian-stimulus-model-stand-the-test-of-time/feed/ 0 All Things Lighting® Association Annual Review – 2022 https://www.allthingslighting.org/atla-annual-review-2022/ https://www.allthingslighting.org/atla-annual-review-2022/#respond Mon, 05 Aug 2024 00:13:15 +0000 https://www.allthingslighting.org/?p=4583 Ian Ashdown, P. Eng., FIES, Senior Scientist CONTENTS HORTICULTURAL Lighting Uniformity in Horticulture A New IES Standard Blooms Lighting Design as a Cross-Disciplinary Science HEALTH Modeling Spherical Irradiance for UV-C Air Disinfection Visible Light Disinfection LIGHT POLLUTION Quantifying Light Pollution Sources Read the full annual report here.

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]]> https://www.allthingslighting.org/atla-annual-review-2022/feed/ 0 All Things Lighting® Association Annual Review – 2021 https://www.allthingslighting.org/atla-annual-review-2021/ https://www.allthingslighting.org/atla-annual-review-2021/#respond Mon, 05 Aug 2024 00:09:55 +0000 https://www.allthingslighting.org/?p=4581 Ian Ashdown, P. Eng., FIES, Senior Scientist CONTENTS GENERAL Defining Far-Ultraviolet ARCHITECTURAL Visual Glare and CIE 117-1995 – NEMA White Paper HORTICULTURAL Horticultural Lighting Design and Déjà Vu The Effect of Near-Infrared Radiation on Plants Specifying LED Colors for Horticultural Lighting HEALTH Ultraviolet Radiation and Viral Misinformation Read the full annual report here.

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]]> https://www.allthingslighting.org/atla-annual-review-2021/feed/ 0 All Things Lighting® Association Annual Review – 2020 https://www.allthingslighting.org/atla-annual-review-2020/ https://www.allthingslighting.org/atla-annual-review-2020/#respond Mon, 05 Aug 2024 00:05:07 +0000 https://www.allthingslighting.org/?p=4579 Ian Ashdown, P. Eng., FIES, Senior Scientist CONTENTS HORTICULTURAL Defining Photosynthetic Photon Efficacy HEALTH Ultraviolet Radiation Terminology Spherical Irradiance and Aerosols Designing an Ultraviolet-C Disinfection System Ultraviolet Disinfection for Consumers LIGHT POLLUTION Greenhouses and Light Pollution Read the full annual report here.

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]]> https://www.allthingslighting.org/atla-annual-review-2020/feed/ 0 All Things Lighting® Association Annual Review – 2018 https://www.allthingslighting.org/atla-annual-review-2018/ https://www.allthingslighting.org/atla-annual-review-2018/#respond Sun, 04 Aug 2024 23:54:18 +0000 https://www.allthingslighting.org/?p=4575 Ian Ashdown, P. Eng., FIES, Senior Scientist CONTENTS GENERAL Rethinking the Photometric Data File Format HORTICULTURAL Far-Red Lighting and Phytochromes Light Transmittance through Greenhouse Glazing HEALTH The Science of Near-Infrared Lighting: Fact or Fiction? Melanopic Green: The Other Side of Blue Read the full annual report here.

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]]> https://www.allthingslighting.org/atla-annual-review-2018/feed/ 0 All Things Lighting® Association Annual Review – 2017 https://www.allthingslighting.org/atla-annual-review-2017/ https://www.allthingslighting.org/atla-annual-review-2017/#respond Sun, 04 Aug 2024 23:35:04 +0000 https://www.allthingslighting.org/?p=4573 Ian Ashdown, P. Eng., FIES, Senior Scientist CONTENTS ARCHITECTURAL Blue Light Hazards and Television HORTICULTURAL Horticultural Lighting Metrics GENERAL Rethinking the Photometric Data File Format DAYLIGHTING Cerise365 and DAYSIM Read the full annual report here.

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]]> https://www.allthingslighting.org/atla-annual-review-2017/feed/ 0 All Things Lighting® Association Annual Review – 2016 https://www.allthingslighting.org/atla-annual-review-2016/ https://www.allthingslighting.org/atla-annual-review-2016/#respond Sun, 04 Aug 2024 23:24:45 +0000 https://www.allthingslighting.org/?p=4571 Ian Ashdown, P. Eng., FIES, Senior Scientist CONTENTS ARCHITECTURAL Sports Lighting Regulations HORTICULTURAL Phytochrome and PSS ENTERTAINMENT Controlling Multicolor LED Luminaires DAYLIGHTING Climate-Based Daylight Modelling LIGHT POLLUTION Mobile Light Pollution Botanical Light Pollution Filtered LEDs and Light Pollution Read the full annual report here.

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]]> https://www.allthingslighting.org/atla-annual-review-2016/feed/ 0 All Things Lighting® Association Annual Review – 2015 https://www.allthingslighting.org/atla-annual-review-2015/ https://www.allthingslighting.org/atla-annual-review-2015/#respond Sun, 04 Aug 2024 23:20:47 +0000 https://www.allthingslighting.org/?p=4569 Ian Ashdown, P. Eng., FIES, Senior Scientist CONTENTS ARCHITECTURAL The Kruithof Curve Kruithof Revisited HEALTH Entraining Circadian Rhythms Seeing Ultraviolet DAYLIGHTING Solar Illumination LIGHT POLLUTION Light Pollution and Uplight Ratings Color Temperature and Outdoor Lighting Read the full annual report here.

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]]> https://www.allthingslighting.org/atla-annual-review-2015/feed/ 0 All Things Lighting® Association Annual Review – 2014 https://www.allthingslighting.org/atla-annual-review-2014/ https://www.allthingslighting.org/atla-annual-review-2014/#respond Sun, 04 Aug 2024 22:57:35 +0000 https://www.allthingslighting.org/?p=4561 Ian Ashdown, P. Eng., FIES, Senior Scientist CONTENTS GENERAL INFORMATION Mesopic Photometry and Statistics – April 21 2014 Solid Angles – July 26 2014 In Search of Luminance – Nov 18 2014 ARCHITECTURAL Thoughts on Color Rendering – Jan 5 2014 Giving Light – May 12 2014 HORTICULTURAL Photometry and Photosynthesis – Dec 10 2014 […]

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]]> https://www.allthingslighting.org/atla-annual-review-2014/feed/ 0 All Things Lighting® Association Annual Review – 2013 https://www.allthingslighting.org/atla-annual-review-2013/ https://www.allthingslighting.org/atla-annual-review-2013/#respond Sun, 04 Aug 2024 22:47:29 +0000 https://www.allthingslighting.org/?p=4565 Ian Ashdown, P. Eng., FIES, Senior Scientist, SunTracker Technologies Ltd. Published: 2013/10/08 Topic: Understanding Mesopic Photometry If you are involved with outdoor area or roadway lighting design, you will undoubtedly encounter such terms as mesopic multipliers, scotopic lumens, and S/P ratios, and you will sooner or later need to consider mesopic photometry in your design […]

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]]> https://www.allthingslighting.org/atla-annual-review-2013/feed/ 0 Lighting R&D Workshop: What is Ideal Light? https://www.allthingslighting.org/lighting-rd-workshop-what-is-ideal-light/ https://www.allthingslighting.org/lighting-rd-workshop-what-is-ideal-light/#respond Sun, 04 Aug 2024 22:41:03 +0000 https://www.allthingslighting.org/?p=4557 Ian Ashdown, P. Eng. (Ret.), FIES Senior Scientist SunTracker Technologies Ltd. U.S. Department of Energy LIGHTING R&D WORKSHOP Co-sponsored by the Illuminating Engineering Society View the full presentation here. Topics Lighting Design Software Today Physically realistic renderings Illuminance and luminance Visual glare (UGR) Daylight factor (DF) Spatial daylight availability (sDA) Annual Sunlight Exposure (ASE) Physically […]

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]]> https://www.allthingslighting.org/lighting-rd-workshop-what-is-ideal-light/feed/ 0 Lighting and Acoustics: Know Your Tools https://www.allthingslighting.org/lighting-and-acoustics-know-your-tools/ https://www.allthingslighting.org/lighting-and-acoustics-know-your-tools/#respond Sun, 04 Aug 2024 02:59:10 +0000 https://www.allthingslighting.org/?p=4552 Ian Ashdown, P. Eng. (Ret.), FIES Senior Scientist SunTracker Technologies Ltd. Concordia University April 2022 View the full presentation here. Whether it is in lighting or acoustics, engineering design and analysis invariably involves commercial software design tools. It can be challenging to master the intricacies of these programs, particularly when they offer idiosyncratic user interfaces […]

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]]> https://www.allthingslighting.org/lighting-and-acoustics-know-your-tools/feed/ 0 Lighting Uniformity in Horticulture https://www.allthingslighting.org/lighting-uniformity-in-horticulture/ https://www.allthingslighting.org/lighting-uniformity-in-horticulture/#respond Fri, 24 Jun 2022 03:34:28 +0000 https://www.allthingslighting.org/?p=2824 Written in 2015, “Greenhouse Design and Control” (Ponce et al. 2015) is extraordinarily comprehensive in its coverage of greenhouse design issues, from site selection through structural load bearing analysis and ventilation technologies to greenhouse automation using adaptive neural fuzzy inference systems. On the topic of greenhouse lighting, however, it has only this to say: “The light level in the greenhouse should be adequate and uniform for crop growth.”

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]]> https://www.allthingslighting.org/lighting-uniformity-in-horticulture/feed/ 0 Modeling Spherical Irradiance for UV-C Air Disinfection https://www.allthingslighting.org/modeling-spherical-irradiance-for-uv-c-air-disinfection/ https://www.allthingslighting.org/modeling-spherical-irradiance-for-uv-c-air-disinfection/#respond Fri, 20 May 2022 13:29:02 +0000 https://www.allthingslighting.org/?p=2791 We have been using ultraviolet radiation as a means of disinfection for over a century. However, it has been the unfortunate events of the past year that have led to an explosion of interest in ultraviolet germicidal irradiation (UVGI) systems. From mercury vapour and pulsed xenon lamps to excimer lamps and ultraviolet LEDs, there have […]

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]]> https://www.allthingslighting.org/modeling-spherical-irradiance-for-uv-c-air-disinfection/feed/ 0 Visible Light Disinfection https://www.allthingslighting.org/visible-light-disinfection/ https://www.allthingslighting.org/visible-light-disinfection/#respond Thu, 19 May 2022 19:45:38 +0000 https://www.allthingslighting.org/?p=2760 In summary, visible light disinfection technology may be useful in some applications, but it is by no means a panacea. When designing or specifying a disinfection system, both the lighting designer and the client will need to thoroughly understand the capabilities and limitations of the technology, and agree upon its purpose.

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]]> https://www.allthingslighting.org/visible-light-disinfection/feed/ 0 Ian Ashdown, Senior Scientist of SunTracker Technologies mentioned in LD+A Magazine https://www.allthingslighting.org/ian-ashdown-senior-scientist-of-suntracker-technologies-has-been-mentioned-in-lda-magazine/ https://www.allthingslighting.org/ian-ashdown-senior-scientist-of-suntracker-technologies-has-been-mentioned-in-lda-magazine/#respond Thu, 07 Apr 2022 06:17:00 +0000 https://www.allthingslighting.org/?p=2751 The IES has introduced ANSI/IES RP-45-21, Recommended Practice: Horticultural Lighting, to describe the differences between architectural and horticultural lighting design. The document is paramount for lighting professionals interested in designing atria, greenhouses and indoor farms.

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