New LED glare concepts based on how humans see

LED luminaires can dazzle, an annoying and potentially dangerous characteristic for street lighting, for example. Matrix LED luminaires in particular suffer from this problem. But thanks to insights into how humans see, new calculation models should do something about this.

By: Dimitri Reijerman

Prof. Ir. Wout van Bommel, who works at Van Bommel Lighting Consultant, will tell us this. during his keynote at the LED event. Van Bommel has done a lot of research in his career into how lighting can cause glare and which standards should be used for this. He says: “We believe that street lighting should provide light that allows you to see the road and other road users well, but that does not blind. There are also requirements for indoor lighting. Scientists have been working on this for quite some time, including me in the eighties. In the design of a luminaire, you can predict how much glare lighting installations can produce.”

But with the advent of LED lighting, from indoor lighting to street lighting, these so-called glare concepts no longer always worked well as a model, says Van Bommel: “Manufacturers of LED luminaires can use the current models to calculate whether a design is blinding. For some LED luminaires, that model is still correct, but for other types of LED lighting it doesn’t work. In particular, matrix luminaires, where you can clearly see every LED dot, can cause glare.”

How we see

Still, Van Bommel thinks that the glare concepts can be improved considerably. Knowledge about how humans see helps with that. Van Bommel: “There is a thought in the world of light that makes it possible to make the predictions correct for new models as well. With these new concepts, you have to go back to how we see things.”

He continues: “In the seventies and eighties we came to the conclusion that part of the retina works like a computer. So-called ganglion cells act as a kind of processor. They do not let all information through, but filter it. Only the important information gets through to the brain.”

According to the 'light professor', processing with ganglion cells can be compared to compressing images on computers, for example to the space-saving jpeg format: "That is a very pleasant method, because otherwise our brains would be too heavily burdened to be able to see alone. The idea now is that that process is the reason why the LED dots of matrix LED luminaires are more blinding. All those dots create too many stimuli for the brain and you start to squint, for example. Based on that concept, new calculation models are now being developed."

New models

Meanwhile, the CIE (Commission Internationale de l'Eclairage) is working on fundamentally new glare models. Van Bommel expects that within one to two years there will be an interim solution that will already improve the prediction. "It's a two-stage rocket," he says. In four to five years we expect very fundamental improvements in the models that are future-proof. A model that better matches how we see."

The lecture by Prof. Ir. Wout van Bommel will be on Wednesday, November 28 at 10:30 am take place in Congrescentrum 1931 in Den Bosch. You can register for a register free visit.