Ian Ashdown, P. Eng., FIES, Senior Scientist, SunTracker Technologies Ltd. Published: 2014/07/26 Do you suffer from math anxiety? A surprising number of us do (e.g., Wigfield 1988). I would tell you the exact numbers, but you would need to understand...
Ian Ashdown, P. Eng., FIES, Senior Scientist, SunTracker Technologies Ltd. Published: 2015/01/21 Lighting design is based in part on the reasonable assumption that photometric units have precise definitions. The candela, for example, has a precise...
Ian Ashdown, P. Eng., FIES, Senior Scientist, SunTracker Technologies Ltd. Published: 2015/10/26 UPDATE 15/11/08 - The following text briefly notes that some people can see near-ultraviolet radiation following cataract surgery due to the UV transmittance of...
Ian Ashdown, P. Eng., FIES, Senior Scientist, SunTracker Technologies Ltd. Published: 2017/03/01 If you perform lighting design calculations today, you can thank the efforts of the IES Computer Committee (IESCC) some thirty years ago. Its members recognized an...
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 is...