Where is the solution to fixing LED lighting?

The answer is that it still doesn't exist. The picture posted here from the New York Times proves that the lighting industry or any other scientific or technical industry still doesn't know how LED lighting works and why it is problematic. If this weren't the case, after multiple billion US dollars going into LED R&D and manufacturing for more than 15 years, we still see LED lamps, like those in the smartphones seen in the picture. Some people see what's wrong with this horrible lighting; others put up with it. Those that CIE and IES call lighting authorities, deny it. Some optics "Exspurts" say microprisms or Fresnel lens, or waveguides can fix LED lighting. So if that is the case, why aren't they used to fix the LED lights in these smartphones?

The truth is, unfortunately, the vast majority of the scientific and technical people involved in optics and LED lighting just don't understand LED illumination. In fact, inorganic LEDs shouldn't be used for illumination unless people who make these LEDs understand why LEDs are directional and why they cause glare; and why it is nearly impossible to reduce glare from high-power and high-intensity LEDs.

Certain IES FIRES articles writtten on LED lights show that the authors don't have a clue about what luminance is. This particular FIRES article got rid of all the comments from the readers. Someday IES will get rid of the article altogether, I am sure. Understanding luminance is only the first step in understanding LED illumination. The other steps are explained in my Get a Grip on Lighting podcast done earlier this year.

Luckily a few people working on LED lighting picked up that LED luminance is the problem. They go about writing on this without quoting my work and that is very unprofessional. When I first brought up the 'luminance' issue, I was called an 'lighting industry outsider' and I was ridiculed. This written comment by a lighting industry authority will be released someday.

Now some lighting veterans are asking me to explain 'luminance'. I assure you if I explain it, people still won't understand LED illumination. You need to go beyond the definition of luminance. I suggest to carefully listen to my podcast and read my paper in ResearchGate.

While that would be a start, this will still not be enough. What will be enough? An academic lecture by me at a well-known university with their top mathematics, physics, and electrical engineering professors present in the audience. All the best R&D LED and optics professionals from the top lighting and optics companies should be there as well. No I won't give you all the answers. I will need to teach you. In order to do that, I'll ask you what you know first. I'll test you on your current knowledge. This is what the best professors do!

The above proposition may or may not happen. I don't mind if it doesn't. It is the choice of the people in the world. The future is in your hands. But I will share with you that NASA Jet Propulsion Laboratory and MIT recently acquired copies of my book. What took them so long when Cornell, University of Michigan, University of Illinois - Urbana Champaign, Berkeley, Stanford, ETH, the library in Stockholm, and hundreds of other well-known universities around the world acquired copies of my book within 2 months of when it first came out? Things take time; but something is happening with the LED lighting industry for sure. The major lighting companies like Philips, Osram, GE and others sold their lighting businesses. Cree also sold their lighting business. This followed the studies that came out of Harvard with the results that LED's blue-rich light content is seriously bad for people and other species. Studies from Madrid followed suit. While these studies haven't determined the real culprit of LED lighting's problems, when the mice or other test subjects are either dead or sick, that is truly a valid data point. While the blue-rich light at high intensity is definitely a problem, you can take a red LED of the same intensity and mice will either die or get very sick if exposed to a very high-intensity red LED. Go ahead - perform the experiment, if you like.

Those that are still in denial that some kind of microprism or other secondary optics will fix the glare of LED streetlights, auto headlights, and stadium lights, or even the lights in the smartphones in this photo shown here, you can publish your full vectorial 3D LID of your fixed LED lamp. I would like to see it! I would like you to explain it to me with that kind of LID, why you think that the glare is fixed.

Finally, no matter how much people deny LED lighting's problems and no matter how much some people like to discredit me, mathematics never lies; and the mathematics of basic physical laws established by Gauss, Euler, Fourier, Lambert, Faraday, and Maxwell show beautifully that LEDs and lasers aren't suitable for lighting unless one substantially alters the Lambertian spatial light distribution they invariably produce. This is very hard to do!

Dr. Nisa Khan

IEM LED Lighting Technologies