The photo above was taken in a windowless room at the centre of a windowless exhibition hall. And no, it hasn't been Photoshopped

Spend more than five minutes in the CoeLux booth at LuxLive and you’ll hear attendees ask the same questions over and over. What void space do you need? Does the light source move? What’s the energy consumption? In essence: what’s the catch? It’s human nature when faced with technology this impressive.

And it is impressive: the skybox is a convincing blue, and the sun-like light source appears distant, creating a mixture of direct and diffuse light which, though not strictly dynamic, certainly feels it. The CoeLux booth where the skylight is on show was situated in the centre of the LuxLive exhibition at ExCeL – an expansive but windowless hall.

The overall impression is that of sunlight pouring into, and bringing life to, a small room, and it does through by creating the same subtle gradations in colour as daylight. To do that it must simulate the atmosphere, and specifically Rayleigh scattering, which CoeLux achieves with a layer of clear polymer with titanium dioxide nanoparticles. CoeLux is now working with Ideaworks to commercialise the technology.

The innovation was recognised last night with a Lux Award for Light Source Innovation of the Year.

‘I haven’t stopped talking all day,’ says Kevin Andrews of Ideaworks, the company that has brought CoeLux to the UK market. Not only was there a  steady stream of people to the stand, but once people got there, they were in no hurry to leave. 

Andrews makes no bones that this is version one, and the technology has further to go. No, the light source doesn’t move… yet. No, the colour temperature isn’t dynamic… yet. The void height needed is a metre. It consumes 340W of electrical power, but that will come down as LEDs improve. 

There’s no shortage of illumination for that power, but the quality of light compared to, say, the seven LV downlights that represent an equivalent power footprint, is in a different league.

CoeLux is at the beginning of its commercial journey, and that’s reflected in the current cost. It’’ll set you back £40,000 from the factory gate, and another £3,000 to £5,000 for shipping and specialist installation. But the interest is already there, particularly for high-value underground installations, like gyms, for instance.

Inventor Paolo Di Trapani delivered an impassioned presentation yesterday about the genesis of CoeLux. ‘This is the sun! This is the sky!’ he told the audience repeatedly, pointing out subtle gradations of blacks in a Rothko abstract, or specific brushstrokes in a Van Gogh self portrait. He barely even mentioned his product, but that didn’t seem to bother attendees, who broke into spontaneous applause as his presentation reached its crescendo.

It felt more like a treatise on light in fine art than on lighting design, but it made one point with extraordinary force: if you want to simulate natural light, you can’t just simulate the sun, you must simulate the atmosphere too. It’s a point proven in spades by CoeLux’s technology. ‘It’s not a lamp. It’s not a luminaire. It’s something else’, Di Trapani says.

If the interest at LuxLive is anything to gauge from, the future of CoeLux is very bright and very blue.