Illuminate the Future of Light and Well-Being at Canada Light Expo 2025 in Toronto, ON
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...
Mesopic Photometry and Statistics
Ian Ashdown, P. Eng., FIES, Senior Scientist, SunTracker Technologies Ltd. Published: 2014/04/21 One of the joys of statistics is that you can never be proven wrong ... In a previous All Things Lighting article titled "Understanding Mesopic Photometry"...
Light Pollution and Uplight Ratings
Ian Ashdown, P. Eng., FIES, Senior Scientist, SunTracker Technologies Ltd. Published: 2015/07/20 "Oh, East is East, and West is West, and never the twain shall meet." When Rudyard Kipling wrote this line in his poem The Ballad of East and West (Kipling...
Cerise365 and DAYSIM
Ian Ashdowna, Chris Jacksonb, Joel Spahnc, Todd Saemischd a. SunTracker Technologies Ltd., Victoria, Canada. b. Lighting Analysts Ltd., London, UK. c, d. Lighting Analysts Inc., Littleton, CO. Published: 2017/02/11 (Updated 2021/04/12) Ceriss365 and DAYSIM are...
Kruithof Revisited
Ian Ashdown, P. Eng., FIES, Senior Scientist, SunTracker Technologies Ltd. Published: 2015/11/24 A previous blog article -- The Kruithof Curve -- examined the history of the Kruithof curve (Kruithof 1941]) shown in FIG. 1: FIG. 1 – Kruithof curve, modern version...
In the Blood
Ian Ashdown, P. Eng., FIES, Senior Scientist, SunTracker Technologies Ltd. Published: 2014/06/25 We most often think of lighting design in terms of lumens, color temperature, and CRI, but there are occasional situations where a deeper analysis is required....
In Search of Luminance
Ian Ashdown, P. Eng., FIES, Senior Scientist, SunTracker Technologies Ltd. Published: 2014/11/18 The IES Lighting Handbook, Tenth Edition (IES 2010), describes luminance as "perhaps the most important quantity in lighting design and illuminating engineering." This...
Horticultural Lighting Metrics
Ian Ashdown, P. Eng., FIES, Senior Scientist, SunTracker Technologies Ltd. Published: 08/04/2017 UPDATE 17/08/26 - This article was first published on August 25th, 2017 in Urban Ag News. It was all so easy until recently. Plants require light in order to grow,...
Giving Light
Ian Ashdown, P. Eng., FIES, Senior Scientist, SunTracker Technologies Ltd. Published: 2014/05/12 Giving light ... this phrase symbolizes a new philosophy of lighting design, a philosophy in the sense of how we think about the lighting design process. Much like the...
Filtered LEDs and Light Pollution
Ian Ashdown, P. Eng., FIES, Senior Scientist, SunTracker Technologies Ltd. Published: 2016/03/03 UPDATE 2016/03/03 - Revised Figure 6. The problem is astronomical -- the blue light emitted by LED roadway luminaires has been shown to contribute to light...