I recently had the pleasure of interviewing Paul Scheidt, Product Marketing Manager, LED Components, Cree. The topic: light and color. I’m happy to share his responses with you here. The interview informed an article I wrote for the November 2017 issue of tED Magazine.
DiLouie: How do LEDs differ from traditional light sources in terms of color characteristics, and what opportunities does this create?
Scheidt: When compared to traditional light sources, like fluorescent or high-pressure sodium, LEDs are not only more energy efficient, but have a broad spectral content that’s not too far away from sunlight. Where many traditional light sources lack color content, LEDs contain a broad spectrum of color. This means that they are able to represent colors more accurately. The biggest opportunity this creates it that the quality of light can be increased while simultaneously decreasing the power load when lighting a space.
Historically, when you went to make things more efficient, it meant the lighting was going to look “uglier” and the color would be off. LEDs have created a new possibility to make the lighting look better and more accurate, while continuing to be energy efficient. Take for instance industries like retail, medical and museums, which have always required a higher quality of light. In the past, they were not able to use energy efficient technologies because that would mean the quality would diminish. However, LEDs present a new opportunity in these fields to maximize color and quality of light while being energy efficient.
Beyond energy efficiency, LEDs present a world of opportunity that traditional light sources do not. As a technology, LEDs allow for the industry to explore new products and innovative designs that were not previously possible. LED technology eliminates the current constraints for a wide spectrum of light applications such as color-mixing, directional lighting and industrial lighting.
DiLouie: With LED technology, it is possible to precisely engineer the spectral power distribution of a product. What possibilities and markets does this serve/create?
Scheidt: Today we are at the forefront of defining and understanding what possibilities and markets are created by being able to precisely engineer the spectral power distribution of a product. The market is trying to push this forward, and most actively I have seen this done from the LED side in the retail lighting application to try to better understand human preference. Though, at this point there is not enough research to figure out what spectral power distributions that humans would prefer to look at, work under or shop with.
However, there are many possibilities that this could create including influencing people, making customers feel more comfortable, increasing worker productivity or creating an environment that is pleasing. This could be a huge economic opportunity for retailers because if customers feel comfortable due to the lighting, there might be a correlation with the number of products they buy or it could influence them to choose a specific store over a competitor. Similarly, there are opportunities here for businesses to increase workforce productivity, for schools to maximize student alertness and hospitals to use lighting for quicker patient recovery.
DiLouie: In 2015, the IES introduced the TM-30 method of evaluating color quality. Do you see designers and manufacturers getting behind TM-30? For what application is the precision of TM-30 ideally suited? What do you think will happen next in terms of new color standards?
Scheidt: Cree was heavily involved in the process for setting the TM-30 standards for evaluating color quality. So with that said, we support the standards and are excited about what they mean for the industry. Right now, the whole industry is still in the process of educating the lighting designers. For the most part, the lighting designers who have heard of the standards and understand them, really like them and see the benefits of getting more information about the light ahead of time, without having to do trials or look at the light. However, like any new standard, it is going to take some time for the industry to understand it, ask for it, find it valuable and make decisions based on TM-30.
In terms of applications, TM-30 is useful for anything where color accuracy and rendering are important in the application. The standard is about understanding how certain light is going to influence colors in the space. So, for certain applications like offices, museums, hospitals, car dealerships this is important, but with other applications, like roadways or parking garages, this may not be as important.
In regards to what will happen next, I think we are in good shape in North America where the industry looks to IES to set standards. However, it will be interesting is to see if CIE, the international body based in Europe will adopt similar standards.
DiLouie: Please describe the process of binning and how standards and manufacturer methods ensure good color consistency. Is there anything new to report in this area in terms of new standards or technology?
Scheidt: Binning is the process of testing every single LED for color and then grouping the ones that are similarly colored together in bins. It can become a rather detailed and complex process depending on the amount of bins and how many bins are necessary to meet a target specification.
The process of binning is relatively standardized across the industry, but which bin you use for colors depends on the product and manufacturer. As a whole, the packaged-LED industry is working on improving the color consistency of the product; the better we can make our production, the better our yields.
DiLouie: The California Title 20 standards require a bump in general-service lamp CRI that may result in 90+ CRI being standard but with the tradeoff being higher cost and potentially lower energy savings. What is your view of these regulations, and (if applicable) how is your company responding?
Scheidt: Cree worked with the California Energy Commission on the development of the 2018 Title 20 requirements, and supports the need for high-quality light in LED bulbs. We believe in the importance of better, and continue to deliver products that offer better light, better dimming, better lifetime and a better warranty.
DiLouie: How important is color to circadian lighting, and where does the industry stand on understanding the science and developing products and a market for it?
Scheidt: The whole notion of circadian lighting is related to influencing your energy levels and emotions through color and light levels– so, color is clearly very important. Over the years, scientists have studied and researched how light levels affect human behavior. For instance, multiple studies have been conducted around humans on submarines and workers who work the night shift; however, studies on the effect of light color on circadian rhythm and what this means are just starting.
To date, I have not seen a product that says it completely understands the science of circadian rhythm, because the industry is not there yet. We have identified the right variables for circadian lighting (color & light amount); however, we do not know where or how you set these controls to impact the biological like mood and energy levels.
DiLouie: Are there any other important new developments in lighting color I’m missing?
Scheidt: As an industry, we are still at the beginning of understanding the notion of mood and human preference for lighting. Past technologies did not allow for the industry to explore and understand these topics the way LED does. Overall, LEDs allow us to think about and design products for the future, as we can manipulate and create new options that we not previously available. They may not be developed yet, but they are now made possible because of LEDs.
DiLouie: Why is color important to understand for electrical distributors selling lighting?
Scheidt: It’s fairly simple – if the color is bad than people are not going to like the product and you will have more returns and unhappy customers.
DiLouie: How can electrical distributors turn their understanding about color into lighting recommendations and sales?
Scheidt: It is not that they always need to recommend the best color performance or the best color consistency into everything. It’s about understanding which customers are going to care about color and which ones aren’t. From the LED perspective, you’re always going to get something with better pricing and performance if you can accept worse color. It’s not always going to be true that people will sacrifice color for price. For them, it’s identifying what the customer tradeoffs are and understanding which customers are willing to pay for better performance and which customers need the best performance.
DiLouie: How should electrical distributors qualify products based on color performance? What performance features, metrics and standards should they be paying attention to?
Scheidt: As discussed earlier, TM-30 is a great standard for electrical distributors to qualify products based on color performance, especially if they want to address the lighting specifier/ designer community. Being able to learn and speak to how the different metrics work will enable them to talk to customers more readily and understand the data that the manufacturers are providing for color sensitive applications. For more mainstream products, the color rendering index (CRI) is still applicable as many industry leaders, such as ENERGY STAR and the DesignLights Consortium (DLC) still use CRI for their color quality metrics.
DiLouie: If you could tell the entire electrical industry just one thing about lighting and color, what would it be?
Scheidt: We are just starting to understand the interaction between color, light levels and human beings, and with LED, have the right technology to help address these needs for the first time in history so expect more change and progress to come.