1. FACULTY OF ARCHITECTURE, DESIGN & PLANNING Shifting Our Vision for Lighting Lux America 2012 Wendy Davis Associate Professor Director Illumination Design

2. Why do we light? 2 We do not light to: Expend / save energy To meet standards & building codes To meet budgets To use particular technologies Image from: http://www.csiro.au/en/Outcomes/Energy/Saving-energy- in-your-home.aspx Image from: http://nyack- ny.gov/departments/building/ Image from: http://rabbishishler.blogspot.com.au/2012/02/soul- budget.html

3. Why do we light? 3 We light so that people can see: Books Faces Artwork Stairways Etc. Image from: http://www.optforhealthyliving.org/ Image from: http://www.guardian.co.uk/world/2010/nov/25/ernest-cole- david-goldblatt-apartheid-photography Image from: http://www.autism-community.com/a- plethora-of-literacy-resources/

4. Fixation with the incandescent lamp The ways we measure, evaluate and communicate about lighting are technology-focused & backward-looking 4 Image from: http://cheaptalk.org/2011/03/18/backward-and- forward-looking-organizations/

5. Correlated colour temperature (CCT) 5

6. 6 + Duv - Duv

7. Colour rendering index (CRI) 7 Reference illuminant Test source Planckian (CCT<5000 K) CIE Dxx Standard Daylight (CCT > 5000 K) Same CCT [K] #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 #14 RaRa

8. Colour rendering index (CRI) 8 = perfect?

9. Colour rendering index (CRI) 9 Neodymium incandescent lamp CRI = 77 (normal incandescent lamp CRI=100) Ref. LED Image from: http://www.ge.com/innovation/timeline/eras/breakthrou gh_discoveries.html

10. Colour rendering index (CRI) 10 3-LED Model Peaks at: 464, 538, 620 nm CRI = 63 Ref LED Image from: http://glassbox-design.com/2009/elos- rgb-led-prototype-changes-colors-on-demand/

11. Further complications 11 Hunt Effect Colorfulness / saturation increases with luminance

12. Moving beyond the incandescent 12 Image from: http://www.eralight.biz/led-bulb/e27- led-bulb.html Image from: http://www.alibaba.com/product- gs/303496832/F96T12_replacement_LED_tube.html Retrofits / replacement lamps: Minimal consumer investment Compatible with existing infrastructure Reversible

13. Moving beyond the incandescent 13 Image fromhttp://news.cnet.com/8301-11386_3-57428951- 76/philips-led-replaces-100-watt-incandescent/ Image from: http://elektro-vault.blogspot.com.au/2012/06/27w-led-to- replace-100w-bulb.html Retrofits / replacement lamps: Difficult to engineer Fail to capitalize on benefits of newer technologies Presume incumbent technologies are optimal

14. Moving beyond the incandescent 14 Disruptive technology “A new technology that changes the current way of approaching a particular problem or issue” 1 1 http://elearningfacultymodules.org/index.php/E-Learning_Terminology Images from: Wikipedia Commons

15. Moving beyond the incandescent 15 Image from: http://www.canstockphoto.com/illustration/imagine.html Let’s imagine…

16. How far could we go? 16 Image from: http://johngushue.typepad.com/blog/2010/06/technolo gy.html Image from: Wikipedia Commons Image from: http://www.cnet.com.au/apple-iphone-4- 339303698.htm Image from: http://dekhomobile.blogspot.com.au/2011/11/latest- glass-mobile-phone-latest-mobile.html

17. How do we get there? 17 Image from: http://www.guardian.co.uk/voluntary-sector-network/2012/jun/13/charity-conduct-strategic-review-advantages

18. Colour vision 18

19. Principle of Univariance 19 The cones transmit no spectral information Countless different spectra can lead to identical patterns of cone activity Perceptions of colour arise from combining and comparing the activity of the different cone classes

20. Trichromacy 20

21. Colour matching functions 21 r(λ) g(λ) b(λ) x(λ) y(λ) z(λ)

22. Colour matching functions 22 x + y + z = 1 (x, y) is a 2-dimensional representation of chromaticity. Y is a measure of visual intensity of light stimulus. x, y, Y fully describe light stimulus.

23. Colour opponency 23 Image from: http://facweb.cs.depaul.edu/sgrais/color_perception.htm

24. Colour opponency 24

25. Colour opponency 25 yellow green red blue DeValois & DeValois (1993)

26. Moving beyond the incandescent 26 Metamers

27. Luminous efficacy 27 Luminous efficacy = radiant efficiency x luminous efficacy of radiation (LER) LER = 408 lm/WLER = 154 lm/W

28. Colour rendering 28 Four lasers Image from: Wikipedia Commons

29. Object reflectance 29

30. Object reflectance 30 Image from: http://greatfruitpictures.onsugar.com/Orange-Fruit- Picture-18993899

31. Visual processing 31 yellow green red blue DeValois & DeValois (1993)

32. Moving forward 32 Spectral design & colour properties Size & shape of lighting products Spatial distribution of light Modes of control & human interaction … Image from: http://gooddisruptivechange.com/why-change- your-mindset/