LEDucation Postponed

Due to growing concerns of COVID-19 in the lighting industry and the New York community, the Designers Lighting Forum of New York is postponing the LEDucation 2020 Trade Show and Conference that had been scheduled for March 17 – 18.

LEDucation is being rescheduled to August 18 – 19, 2020.  I expect that our TM-30 Annex E seminar and demonstration room will be part of the rescheduled event.

LEDucation Update

LEDucation this year is on March 17 and 18 at the New York Hilton Midtown where our Jason Livingston be part of two presentations.  The first, at 9 am on Tuesday morning with Wendy Luedtke of ETC, is a seminar called Specifying Color Rendering with TM-30’s New Annex E.  The session presents the new ANSI/IES TM-30 Annexes E and F, which apply recent research to identify three color rendering design intents (Fidelity, Preference, and Vividness) and provides specifiers with TM-30 values to achieve them alone or in combination. Our goal is to increase awareness of Annexes E and F and to help attendees better understand their contents and use. The seminar is most appropriate for people with some prior knowledge of TM-30, although there will be a brief TM-30 overview for those who are new to the topic.

Then, on Wednesday, we’ll be joined by Jess Baker of Schuler Shook for a daylong demonstration of Annex E.  In the TM-30 Demo Room visitors will experience an immersive mockup illuminated with a variety of light sources illustrating the Annex E design intents. The lighting demonstrations will be paired with TM-30 values to show how TM-30 can be used to select light sources for each intent. Visitors will experience sources that meet different levels of the IES TM-30 specification guidelines outlined in IES TM-30-18 Annex E.  We’ll be presenting the demonstration on the hour and half hour from 9 am to 2 pm.

You can register to attend LEDucation here.

Using TM-30 to Improve Your Lighting Designs

Recently, ANSI/IES TM-30 was improved with the addition of Annexes E and F.  Annex F reviews and summarized five studies that explored using TM-30 metrics to predict subjective visual outcomes.  Annex E uses that research to establish recommended specification criteria when the designer’s color rendering goals are Preference, Vividness and/or Fidelity.  

The IES Forum for Illumination Research, Engineering, and Science (FIRES) has an article I wrote with Michael Royer and Tony Esposito explaining the Annexes and how to use the information in Annex E.  Here’s the link: Using TM-30 to Improve Your Lighting Design – Illuminating Engineering Society

I’ve been using Annex E on projects and have spoken to other designers who have begun to use it.  It provides useful, accurate information that allows me to evaluate the color rendering results of light sources in a way that hasn’t been possible until now.  It lets me make informed decisions about my projects, and explain those decisions to colleagues and stakeholders in (relatively) easy to understand terms.  

TM-30 and the TM-30 calculators continue to be a free download from the IES here.  Annexes E and F are also free on the Errata and Addenda page here and here.

Do LEDs Make You Look Orange?

Last Thursday Donald Trump spoke to a group of Republicans in Baltimore.  One of the things he said caught my attention: “The lightbulb. People said what’s with the lightbulb? I said, here’s the story.  And I looked at it, the bulb that we’re being forced to use, No. 1, to me, most importantly, the light’s no good. I always look orange. And so do you. The light is the worst.”

Now, I’m not aware of being made to look orange under LEDs, nor have I ever noticed LEDs making my friends, colleagues, or students appear orange.  You can’t imagine how embarrassed I’d be if it turned out that a real estate developer and entertainer had more astute color perception than me, a lighting designer and Co-Chair of the IES Color Committee.  If our only means of evaluating the color rendering of a light source, and evaluating the orange content specifically, was CRI we would have no objective way of testing his statement.   CRI, technically Ra, is a single value that gives us an average of the match between the light source in question and its reference source (either a blackbody radiator or a CIE definition of daylight, depending on CCT) using only the eight color samples shown below.

8 colors used to calculate CRI

Since Ra is an average value there’s no way to understand the rendering of any particular hue. I’ve talked about this here. However, one of the wonderful things about ANSI/IES TM-30 IES Method for Evaluating Light Source Color Rendition is that we can use it to test that claim.  TM-30 uses 99 color samples that are distributed across the color space and the visible spectrum, as shown below. 

99 colors used to calculate TM-30 metrics.
TM-30 color sample spectral reflectance functions

It also breaks the color space up onto 16 Hue Bins, each one covering a specific range of the color space, again as shown below.  In the case of orange, we want to look at Hue Bin 3.  Specially, we want to look at Rcs,h3 (the subscript CS stands for Chroma Shift) which quantifies the increase or decrease in the saturation or vividness of orange compared to the reference light source.

TM-30 background graphic
example of chrome shift bar graph

So, let’s put the science of TM-30 to work and see if we really do know that LEDs make us look orange!

The TM-30 calculator contains a library of 300 SPDs (spectral power distributions), of which 137 are commercially available white LEDs.  The CCTs range from 2776 K to 6123 K.  If white light LEDs really did make us look orange we’d expect to see a large majority of them have a positive Rcs,h3, probably with an average chroma shift in excess of 10%.  In fact, the 137 SPDs have Rcs,h3 that range from -8% to 1% with an average of -3.6%, a decrease (not an increase) in the saturation of orange.  It’s not me, it’s him.  TM-30, which uses the most modern models of human vision and a set of colors that cover the color space and visible light spectrum, proves it.  What a relief!  

Don’t believe me?  Download TM-30 and the calculator for free from the IES web site and see for yourself.

Of course, I’m not saying LEDs are perfect light sources. Like any other product there are good ones and bad ones. However, TM-30’s measurements of fidelity and gamut (as averages) and measurements of fidelity, chroma shift, and hue shift (by hue bin) permit us to make a thorough evaluation of a light source to understand its color rendering characteristics. Using this knowledge, we can determine if a particular light source distorts colors and is appropriate for a project, or not.

I should take a moment to note another error he made when he said, “And very importantly—I don’t know if you know this—they have warnings. If it breaks, it’s considered a hazardous waste site. It’s gases inside.”   Perhaps you’ve heard the acronym SSL or the phrase solid state lighting.  LEDs are a version of SSL, which means that they are…well, solid. Unlike previous light producing technologies LEDs are a solid combination of materials.  As such, if one were to physically break (which is unlikely since LEDs are small, are mounted to a heat sink and often covered with a lens, so you’d have to break a lot of materials simultaneously) no gas, hazardous or benign, is emitted.  He’s thinking of fluorescent lamps and the small amount of mercury they contain.  Even then, a broken fluorescent lamp doesn’t turn the area into a” hazardous waste site.” Here are the EPA’s instructions for cleaning up a broken fluorescent lamp.

Video: White Light and Color Appearance

Earlier this year our Jason Livingston taped an hour long presentation on White Light and Color Appearance as part of the IES Lighting Education Facility Showcase series for New York School of Interior Design. The presentation is now available to stream! It’s hosted on the IES web site so we can’t show it here, but here’s the link. Have fun!