Lighting : February 2014 Lighting (v2-HR)
14 LIGHTING MAGAZINE | February/March 2014 FROM THE EDITOR This special issue of Lighting is being distributed at Light+Building (Hall 11 Foyer), the giant biennial lighting fair in Frankfurt. If you are reading Lighting for the first time in Frankfurt, I hope that you enjoy the range of features in this issue, including the information about the lighting industry in Australia and New Zealand. It will be interesting to see if Frankfurt presents the industry with anything that is really new in the evolution of solid state lighting (SSL). I emphasise the word lighting because lighting is the application of light for human endeavour: seeing. The early days of SSL were dominated by people who knew about solid state physics but little about lighting and in particular how people see and what the visual system needs for both work and pleasure (at least, freedom from injury and discomfort). The early fantasy was RGB LEDs for all white light applications. That was quickly put to the side as the issues with colour stability, ageing, control, etc, were seen as difficult and expensive; best left to the (expensive) theatre luminaires and the signage industry. The binning of RGB in favour of a blue LED plus a phosphor also helped with achieving reasonable colour appearances under white LEDs because the phosphor is very broadband compared with the almost monochromatic RGB LEDs. The hype and the spin are fine tuned as the changes occur. Hopefully, we are nearing the end of the blinding glare phase of the development of SSL. Blinding glare is effective in creating vehicle conspicuity from daytime LED running lights. Most people find blinding glare, either directly or by reflection in gloss surfaces, very uncomfortable, distracting and ugly in interior lighting. The high- end luminaire manufacturers eschewed LEDs until an acceptable number of major issues had been sufficiently resolved (not necessarily solved) to allow them to produce LED luminaires without destroying their reputations. So, we can now buy quality low-glare LED luminaires. Interestingly, glare control is often achieved using diffusion. This not only reduces the luminance of the individual LEDs or “lamps” but it can eliminate the appalling dots, so characteristic of (bad) LED lighting, by scattering and diffusing the light. With traditional sources, diffusion had almost disappeared in favour of reflection and refraction because these are more efficient at redirecting light than diffusion. Diffusion, whilst inefficient, suits the tiny LED sources. Diffusion also means that there is less shouting about lumens per watt. It seems to me that the quality end of the market is achieving similar luminaire performances to best quality T5 tubular fluorescent (including “lamp” life). LED performance is generally better that low wattage metal halide. So, it is encouraging to see some maturity in the SSL industry, if only at the top end of the market. Unfortunately, the rest of the market is still in what could best be described as a state of chaos, with too many players, producing thousands of products with unknown lighting and electrical performance. Most of these products will be throw away, since the concept of spare parts and repairs does not seem to exist in most of the SSL world. I think that I will have to await the next fair in 2016 to talk about the much promised but rather shy OLED’s role in lighting. Finally, I hope you enjoy this issue and in particular, the comments of women in lighting design. Warren Julian Editor Do the merging dots herald the dawn of SSL maturity?
April May 2013
Lighting April 2014 - Vol 34 Issue 2