All this talk about lumens distract us from what really matters in lighting, opines Lance Stewart of Creative Lighting.

Back in the 70s, in an age when real men wore such amazing superclothes as platform shoes that made you taller than a Harlem Globetrotter, trousers (called flares) that were so wide at the hem they could have demanded their own bus seat and shirts that sported collars so big they could lift you off your feet during a stiff breeze, we poor members of the lighting profession faced an uphill battle because lighting was under-appreciated by those who decided how much to spend on lighting for projects. The sorry state of our trousers would not be mended quickly by working only with lights.

As the 70s gave way to the 80s, little had changed. Fast food ‘restaurants’ were still uniformly lit by cheap monophosphor fluorescents that drained colour out of their products and customers faster than a V8 motorcar could drink gas. Women would take a chosen frock outside into sunlight because they thought department store mirrors made it impossible to judge its real colour. Streets were lit by low pressure sodium vapour lamp luminaires that pooled light like yellow pus. And everyone thought they were a lighting expert because they could go down the road and buy a portaflood, plug it in and aim it at a mirror ball. Ah, the good old days.

 It took years to educate the market about the advantages of good lighting; years spent thumping tables, pressing flesh (read into that what you will) and passionately demonstrating the wonders of light. Fast forward a few decades and the rampant success of lighting – thanks to all that market education by passionate lighting designers telling a cohesive story – is being undermined, because that story is being drowned out by a cacophony of confusion and crap, a preponderance of poor luminaires hiding some genuinely brilliant ones and the bandying about of sciencey-sounding terms like ‘CRI’ by far too many people who probably don’t know what a chromaticity chart is. Or, far more importantly, what constitutes good lighting.

Let’s get something straight: LEDs are rightly revered as the wonder boys on the block. No other type of light source has ever managed to usurp so many other light sources (incandescent, fluorescent, discharge and so on) in the history of lighting. And LEDs are following Haitz’s Law, which basically means that their ‘bang for buck’ is ever-increasing.

Nobody gives a sh*t about the source

But LEDs are just light sources: they aren’t the ‘be-all and end-all’ of good lighting and they should not be the main subject of conversation with potential clients who, let’s face it, probably care less about the light source you put in your luminaire than they do about how televisions obtain, combine and display the audio and video signals that somehow become Game of Thrones. They just want the sex and violence, not a lecture about how it made its way into the TV in their living room.

So what’s changed to make the story muddled? The advantages of good lighting and the potential benefits to end users have not changed. Yes, we can now control lights with open protocols and tablets and smartphones and that’s all good. And yes in many cases the capital cost has gone up, but running costs have come down – so the accountants are happy. Great, terrific. But the usable properties of light have not changed – they can still be summarised as colour, distribution, intensity and movement (in the sense of change over time). And yet what a lot of people are shouting about is none of these things. Now it’s all about the LEDs – riveting subjects like thermal management, CRI and lumens. True, I did once talk about ‘initial’ or ‘design’ lumens when comparing alternative light sources that could be interchanged in the same luminaire. But that’s a far cry from being constantly bombarded by people wanting to talk about lumens.

Don’t get me wrong, I’m really happy for you that you have an LED that is greater than 200 lumens per watt. Thrilled, really. But it would be remiss of me not to mention that no professional lighting designer actually gives a shit about something’s possible light output – what they (and their customers) care about is what the lighting will actually do for them. Things like the consistent quality of the light over the course of its life, how that light is modified and controlled, how much light (intensity] actually gets out of the luminaire and where that light goes. Yes, we want to know the CRI and when the answer is less than 90 (as it so often seems to be) we also want to know the R9 value, but only so we know how much we have to compromise on the 100 out of 100 rating that we were all selfishly accustomed to thanks to incandescent luminaires.

A happy ending, or back to the 70s?

And yes, we do care about the environment and have power unit densities to consider, so the lower the energy the better, provided the luminaires on offer support our goal of good lighting practice. And not only do we care what the beam angle is, we also want to know the field angle too damn it, because there seem to be rather a lot of isolux plots for LED luminaires (and not all come with a plot at all) that don’t mention that the tenth peak cut-off is actually somewhere in the neighbour’s yard. And don’t even start me on glare, a concern I recently raised only to be wisely rebutted by a lighting salesperson who informed me that people don’t look up – or at – lights anyway. Well that’s good then.

And as for the ever-increasing warranty periods for LEDs, I have this to say: Warranty periods are not a sure-fire indicator of good quality lighting, let alone any guarantee about the expected longevity of the company that offers it. Even bad products can have a warranty period longer than the age of the universe. How, you ask? Simple: Once I have removed power from the offending lighting, it’s off and it will bloody well stay that way for eternity if I have anything to say about it. Guaranteed.

So let’s get the story straight: good lighting can transform the mundane, highlight, hide the ugly, enhance the attractive, set the mood, change as needed, and even motivate people to buy your client’s crappy products. It’s a good story with a happy ending for all of us in the wonderful world of lighting. And it means we can all afford to buy a decent suit now and then.

But we need to talk the talk like we used to, or get ready to walk the walk like we used to – in a pair of rather fetching flares with our arses hanging out.