Who Needs A Lighting Designer? Schools!

Studio T+L is the theatre consultant on the theatre in a new school here in New York. During an early meeting with the architect I explained that I prefer to have the dimming and control system for the stage lighting also control the house lighting, so I’d like to schedule a meeting with the lighting designer to talk about coordinating our work.

I wasn’t surprised (although I was disappointed) to be told that the design team for this new school building doesn’t include a lighting designer. Who’s designing the lighting in the classrooms, offices, theatre and other spaces? It’s hard to say. The plan is that one of the architect’s lighting sales representatives will present them with a choice of light fixtures, the architect will select the fixtures, and the electrical engineer will lay them out and circuit them. Unfortunately, this is an all too common approach that results in mediocre lighting, at best. Here’s why…

For starters, it’s highly unlikely that the architect has a deep enough understanding of vision, visual tasks, current fixture technology, control technology, code requirements, and the lighting design requirements of educational facilities to thoroughly evaluate the lighting needs of the school and the various types of spaces that it holds. It’s much more likely that the architect is working with a possibly outdated rule of thumb such as, “Schools should be lit to 50 fc.” The sales rep, even if he/she is capable, isn’t going to invest any time or effort in a deeper evaluation of the school’s needs because the fixture sale (not good lighting) is the goal, so meeting the architect’s requirements is all that he/she has to do. The electrical engineer is simply implementing the architect’s instructions. He/she is given the selected fixtures and told to arrange them to provide 50 fc, and make sure to cover the code requirements. What’s missing is any thought about how the spaces will be used and the actual needs of the occupants .

I believe that design is as much a process as it is a product. A lighting designer would not assume that all school lighting is the same, and that as long as there’s enough light the lighting will be good enough. A lighting designer would talk to the school about their present facility, and about the good and bad aspects of the current lighting. The lighting designer may consult one or more of the available guides to quality lighting design for schools such as ANSI/IES RP-3-13 Lighting for Educational Facilities, and would look for opportunities to include daylighting as one element of the overall lighting design. A lighting designer would look at the sustainability and energy efficiency aspects of the lighting system and factor that information into the overall design. A lighting designer would take the time to understand how various types of classrooms are used, and would lay out fixtures and select controls accordingly.

I’m sure that none of this is happening on this school project.

And, not just any lighting designer will do. It behooves architects to have some understanding of the lighting needs for the building types they design to make sure the lighting designers they hire doing their job. For example, my classes at Parsons School of Design in Manhattan are held in a building that is less than five years old. It that was designed by a prominent architect. However, the classroom I was in last semester had terrible lighting. The room has two rows of direct-indirect pendant fixtures. The uplight and downlight components are controlled together, and all of the fixtures are controlled by one dimmer, so all of the lighting in the room works as one. The problem? The projection screen is bathed in light that washes out the image, and there’s no way to dim or turn off only the fixtures that affect the screen. There are lighting controls by the door, but none by the instructor’s computer station, so I find myself walking back and forth across the room to make adjustments to the light as I constantly balance my students’ need to see the screen with their need to see their notebooks. This is a rookie mistake, and any experienced designer worth his or her salt should have immediately seen the potential problem and selected fixtures, a layout, and controls to avoid it, but it didn’t happen.

So, who needs a lighting designer? Schools and the architects who design them.

NEMA Misrepresents IES TM-30

On November 12 the National Electrical Manufacturers Association (NEMA) published a position paper on IES TM-30-15. The document is here. It seems to be a willful misunderstanding and misrepresentation of TM-30. Here’s how…

The paper opens with NEMA’s support of an improved color metric but then goes on to say that “NEMA opposes any mandatory reporting or performance requirements for IES-Rf or IES-Rg.” This is a strange opening since neither the IES, in general, or TM-30, in specific, is proposing mandatory requirements. In fact, the IES’s own position paper on this states that “As with any IES Technical Memorandum, TM-30-15 is not a required standard.” So the paper begins with alarm about a non-issue.

Next, it says that, “Any single-number fidelity measure (such as Ra or the new Rf) that averages the results of many colors in a light source could possibly have a high numerical value and yet perform poorly with some specific colors.” Exactly. That’s the problem with CRI Ra, only a single number is reported. The great advantage of TM-30 is that in addition to the average fidelity value Rf, the calculation tool allows designers to see 1) the fidelity within color groups, called Hue Angle Bins, that encompass the entire color space 2) the direction of hue shift (if any) as displayed in the Color Vector Graphic, and 3) the Rf for each of the 99 Color Evaluation Samples (CES). Far from being a single value, as with Ra, TM-30 provides designers with layers of additional information about the performance of the lamp in question.

In the next paragraph we are told “The IES-Rg metric can have a value greater than 100 and yet saturation might be lower than the reference light source for certain colors.” Right again, but in a misleading way. As with color fidelity, TM-30’s evaluation of color gamut is layered. Rg represents the average shift in saturation of the 99 CES. If a specifier wants deeper information it is available in the calculation tool as 1) a CES chromaticity comparison that plots the CES under both the reference illuminant and the test source so that one can see the shift 2) a graph showing the change of chroma by Hue Angle Bin.

The entire third paragraph complains that if Rf is 100 there can be no increase or decrease in Rg – saturation is held at 100, too. This is like pointing out that the problem with taking a bath is that you get wet and soapy. The interrelation between Rf and Rg is a feature, not a bug. When the fidelity index of a light source matches it’s reference then OF COURSE they will produce the same saturation of colors. If one wants to purposely increase or decrease saturation the only way to do so is to use a light source that is NOT an exact match to the reference source, and hence one that has a lower fidelity value. The relationship between Rf and Rg are shown as a graph in the calculation tool to help designers visualize the values that the tool calculates. That’s a good thing.

Finally, the paper concludes with “It is premature to consider IES TM-30-15 as a mandatory requirement or regulation because the metrics are likely to evolve.” As I said at the beginning, this is a non-issue.

The IES developed and issued TM-30 because CRI does not consistently and accurately represent the color rendering of many light sources, especially narrow band emitters like LEDs. This issue is well known and completely accepted by the industry, including the CIE. (A list of CRI’s shortcomings is included in the latest edition of the IES Lighting Handbook.) The IES position is that TM-30 “has been developed for the benefit of the lighting community to provide: (a) a more accurate assessment of color fidelity; (b) an additional, complementary assessment of the influence of the preferred color appearance of objects (related to color gamut); and (c) more detailed information about the rendition of specific colors.“ and goes on to say that, “the issuance of TM-30-15 will enable the international lighting community to carefully evaluate it, providing a path leading to improved standards and design guidance. Technical analysis and feedback regarding the method described in TM-30 will be critical to continued development and standardization of color quality metrics.” In other words, “We think this is a good tool. We’re publishing it so that other concerned parties can evaluate it. We hope that this will trigger the acceptance of TM-30 or the development of another tool.”

Clearly NEMA as an organization, or members of their Lighting Systems Division, has a problem with the IES issuing TM-30, but the position paper is a red herring. It stirs up alarm over TM-30 becoming a requirement or regulation when the IES has noted that isn’t the purpose of a TM, and attempts to point out shortcomings that actually belong to CRI, not to TM-30. I don’t know about the politics involved here, but I do know that this paper should be read with skepticism.

Who Needs A Lighting Designer?

No I’m not begging for work (although I am available for weddings and bar mitzvahs). At the beginning of every semester I ask my interior design students (especially at Parsons, where the class is an elective) why understanding lighting design is important to them. They tell me that lighting design is important for setting the mood or atmosphere, that lighting affects the appearance of materials and finishes, and that light is an important element in the overall design of any space. Good job!

But, as we move through the semester they often say that there’s so much to know and ask if interior designers, architects, and electrical engineers really know all of it. If not, why do only 10% of construction projects have a lighting designer? Why isn’t a lighting designer assumed to be part of a design team just like an electrical or mechanical engineer?

So I did a little research. According to the DesignIntelligence ranking of the top five interior design programs, only three undergraduate and one graduate program require a semester long course in lighting design. It turns out that I’m in a fairly unique situation in that my undergrad interior design students at Pratt are required to learn about lighting design.

What about architects? According to Architectural Record’s ranking of the top ten undergraduate and graduate architecture schools, only one grad program, and zero undergrad programs, require a course in lighting design! So, at least in the U.S., we shouldn’t expect interior designers or architects to create more than utilitarian lighting because they’re not educated in the practice of lighting design. Yes, many care quite capable of laying out a lighting plan that meets code requirements but we should remember that codes set minimum requirements for safety and energy efficiency. Codes have nothing to say about appropriateness for the application much less anything to do with aesthetics of the space or the interaction between light and materials.

So what do I tell my students? In the same way that there’s a difference between a decorator and an interior designer, there’s a difference between someone who can “do lighting” and a lighting designer. The differences are many, actually, and include academic education and training, continuing education, range and depth of experience, and a focus on the practice lighting design as a profession and a livelihood, not as an ancillary service. I tell them that it’s important for them to be able to speak the lighting designer’s language and to understand the interaction between light and materials because lighting can have such a strong effect on their work. I tell them that they may find themselves lighting some of their own projects and I hope my class prepares them for that. In the end I also tell them I’m sure they’ve learned that the best lighting designs are created by a professional lighting designer. If they want the best for their clients and their work, it’s worth the extra fee and worth talking to the client about what a lighting designer can do to support and enhance the project. Everyone needs a lighting designer, they just don’t know it.

Light and Health Webinar, September 30

Almost as if on cue, Philips Lighting is hosting a webinar on light and health presented by Mariana Figuerro, the Light and Health Program Director at Lighting Research Center. I attended one of her in-person seminars earlier this year and I can say that she does a great job of explaining what aspects of light and health we can integrate into our practice now, and what aspects need additional research. You can read more about the webinar here, or go straight to the registration page here.

Use of LED Lamps To Improve Health

Today’s New York Times has an article on several manufacturers’ new LED products that are intended to improve wakefulness, sleep, focus, and other aspects of daily life and health. The article appears on both the business and technology pages, but not on the health page, and I think that’s appropriate. Although there are testimonials by the consumers of some of these products, there’s no discussion about any peer reviewed science behind them. In fact, about two-thirds of the way through the article the author finally gets to the fact that, “Researchers are still determining how spectrum and intensity of light affect the brain.” So, the article is an uncritical look at new LED products that make health claims. We shouldn’t rely only on the claims of the manufacturers, though – remember the claims of 100,000 hour lifetimes for LED lamps?

I’m not saying that we know nothing about how light affects us, because we know quite a bit. The question is, “Do we know enough to properly and safely integrate that information into our design practice?” and there things become uncertain. So, before accepting the claims of manufacturers, or making the same claims to clients, it’s important for designers to be up to date on the current state of research and to understand the strength of the findings, as well as how (and if) those findings can be folded into a design.

There are a few web sites that I find useful for keeping up to date. The first is the Health and Vision page of the Lighting Research Center’s web site, which has links to many of their recently published research papers. The second is the Research page of USAI Lighting’s web site. This page provides links to a mix of newspaper articles and scholarly publications on a variety of topics connected to LED lighting. The third is the Research page of the IES web site. Finally, members if the IES can download copies of Leucos, and non-members can purchase copies.

LEDs continue to revolutionize the lighting industry. Most manufacturers have ended research and development for incandescent and fluorescent products. OLEDs are increasing in efficacy and prices are dropping, while new technologies (such as light emitting plasma and quantum dots) are on the horizon or already here. To preserve their client’s money, the occupant’s health and safety, and their own reputations, designers need to make sure that they don’t get swept up in the possibilities that are marketed to them before the facts are in.

“Celebrating Pratt Authors” Comments

Here are my comments from last night’s “Celebrating Pratt Authors” event.

Let me say a few words about my book and than I’ll move on. One of the things that drive me to write “Designing With Light” is missing content in other lighting design books. I come from the theatre-both my undergraduate and graduate degrees are in design for the stage, and I worked in the theatre for over a decade before transitioning to architectural lighting. The other two common paths to becoming a lighting designer are from work as an architect or as an electrical engineer. Until now, as far as I can tell, lighting design books have been written by people with those two backgrounds. They do a fine job of discussing how to light architecture and how to calculate illuminance, but none of them actually address the issue of design. None of them discuss how to think about light as a design element in a space, or how to use light to create the desired atmosphere, environment, or ambiance. That’s the void I wanted to fill.

Some of you may know that the United Nations has designated 2015 as the International Year of Light. I want to build on this by saying a few words about the importance of light and lighting design. There’s an old saying, “out of sight, out of mind” but with lighting design the truth is actually closer to “within sight, out of mind.” Too often people ignore or are unaware of the potential that lighting design offers because as long as they can see they’re satisfied. Many people only notice light when it’s beautiful, as with a sunset, or when it’s an impairment, as when there’s not enough light to do what they want to do. Yet, while only a small percentage of people are aware of the lighting in their surroundings, 100% of people are affected by that lighting.

Sight is, without a doubt, our most important sense. Research shows that about 80% of our sensory input, learning, and activities are related to vision.

Our visual interaction with the world, and has two components. The first is target or object identification. “I see and apple,” is an example of object identification. However, our minds are much more sophisticated than that. We don’t stop at object identification. We’re not really aware of it, but we automatically go on to evaluate our visual target and its relationship to the surrounding visual field, to our previous experience, and to our expectations. This second component of vision is perception-the identification, organization and interpretation of sensory input. Perception is directly affected by the way light reveals the world to us. Can we see the texture of a material or not? Is the color as expected or is it distorted? Can we see the three-dimensionality or does the object appear flattened? Are details visible or are they hidden in shadow? Lighting design matters, in part, because it affects our perception.

The lighting requirements for object identification in terms of brightness, color, direction, etc. are minimal. However, the effect light has on our perception is huge. Perception causes us to form opinions about, and have intellectual and emotional reactions to, everything we see.

If I were to say that I want to take you to a romantic French restaurant, every one of you immediately has a mental image of that space. You may have a mental picture of the color palette of the room, or the ceiling height, or the spacing of the tables. That image varies from person to person, but there is a remarkable amount of commonality in our expectations. For example, I’ll bet that in your restaurant there’s a candle on the table, that the lighting is dim, and that the wood is dark and polished.

If we walked into a restaurant that we have been told is romantic and find it illuminated like a classroom, the perceptual dissonance between our expectations and our experience would cause us to immediately reject the notion that we were in a romantic restaurant. We would declare that the lighting design was a failure. We would, perhaps, extend the idea of failure to the interior design and, depending on the strength of our emotional response, maybe even to the food. Lighting matters, and understanding how expectations of the users affect their perception is one aspect of creating a successful lighting design.

This is something that I emphasize to my students all of the time – you must understand the intended look and feel of the space before you can light it. I also emphasize that they must understand the distribution of light in three dimensions, not just in a two-dimensional plan view.

To control the three dimensional distribution of light requires an understanding of the many types of lighting fixtures that are available, and of the light sources that they use. To control those light sources we have to know about dimming and control systems and technology. The body of knowledge required to create a lighting design is very large.

And, it’s getting larger every year. New lighting technologies such as LEDs and OLEDs have some unique properties. To use them well we have to expand our understanding of issues such as color and control technologies. Add to that the fact that energy conservation codes compel us to think much more carefully and creatively about what we do and how we do it because we’re given so little electrical power to realize our design goals.

Add all of this up and we find that lighting design is hard! It requires a solid grounding in light sources, fixtures, controls, and codes. All of that technical expertise has to be combined with a broad understanding of architecture, interior design, lighting techniques, and aesthetics to turn a mental vision or a rendering into a realized design.

I get very excited when I talk about light and lighting, but I’m frustrated, too. Only about 10% of design and construction projects include a lighting designer on their team. For the other 90% of projects, the lighting design is handled by the architect, the interior designer, or the electrical engineer. Yet academia is not providing the lighting education future designers need.

I’ll use Pratt as an example. Not only is lighting design not a required course in the any of the architecture programs, it isn’t even an elective. Students have to go to the Interior Design department if they want a semester of lighting, but that course is going to be eliminated within a few years as the Interior Design department reorganizes. Pratt is just a single example of what I think is an overall disregard or failure to understand the way light affects our experience of the built environment, and the need to teach future designers how to address the entire visual experience. This, of course, takes us right back to “within sight, out of mind.” But, good enough lighting isn’t good enough.

So, in this International Year of Light, I want all of you to think about and talk about the importance of good lighting in your homes, at work, an in the other places you spend your time. If you teach architecture or engineering or interior design, I urge you to give lighting design a place on the curriculum. If you’re a student I want you to demand that lighting design be made a part of your education. The International Year of Light has set the stage, but it’s up to us to act, to raise the importance we place on good lighting.

With LEDs, Knowledge is Power

I’ve been hired to review an architect’s lighting design and then design an appropriate control system. The fixtures selected are all LED products by a manufacturer that falls into the high-end residential/economy commercial range of quality and price. The cut sheets are extremely frustrating. After nearly a decade of LED lighting, and with all of the progress the industry has made in setting standards so that designers and specifiers know what they’re getting, this manufacturer still tells us nothing. What basic information is missing?

Lamp life. The only information even remotely connected to lamp life is the statement that the fixture is covered under a five-year warranty. There’s nothing else. Not a word. How much light, compared to initial output, can we expect at that five-year mark? We have no idea.

LEDs do not fail like other lamps do. They gradually dim as they age. At what point is the light output so low that we’d say the lamp is no longer useful? Right now the answer is when the light output has fallen to 70% of the initial output (often referred to as L70), although many designers prefer to use 80% of initial output (referred to as L80). This is calculated using a procedure developed by the IES and designated as LM-80 (details are here and here). What we want, at a minimum, is the IES LM-80 calculation of lamp life to 70% of initial output. L80 data would be even better.

Warranty. The warranty is not on the manufacturer’s web site so, although we’re told that it is good for five years, we have no information about what is covered and what is excluded.

LED manufacturer. With all other lamp types the designer chooses the exact lamp for the project. Criteria such as initial lumen output, mean lumen output, lamp life, color temperature, CRI, and the manufacturer’s reputation for quality are all valid considerations. We have standards that allow designers to make valid comparisons between LED products, too, but we can do that only if that information is generated and shared. I suspect that this fixture manufacturer uses LEDs from a several manufacturers based on the best price available, and that the performance of those LEDs varies widely.

Color consistency. The cut sheet says that the standard applied to their LED selection is, “minimum 3-step color binning.” We are left to infer that means three-step MacAdam Ellipses. A one-step MacAdam Ellipse describes a region on a chromaticity diagram or color space where the edges of the ellipse represent a just noticeable difference from the color at the center (additional information on MacAdam Ellipses is here and here). The data is usually plotted on the CIE 1931 (x, y) chromaticity diagram. The diagram below shows 10-step MacAdam Ellipses.

"CIExy1931 MacAdam". Licensed under CC BY-SA 3.0 via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:CIExy1931_MacAdam.png#/media/File:CIExy1931_MacAdam.png — “CIExy1931 MacAdam”. Licensed under CC BY-SA 3.0 via Wikimedia Commons – http://commons.wikimedia.org/wiki/File:CIExy1931_MacAdam.png#/media/File:CIExy1931_MacAdam.png

The color variation within a three-step ellipse would be noticeable to over 99% of the population. Worse, though, is that a three-step ellipse is the minimum, not the maximum. Knowing this, the designer should have no expectation of color consistency from one fixture to another.

Photometrics. The cut sheet contains no information about the optical performance of the fixture. IES files are available, but it’s very difficult to look at the array of numbers and understand performance, which is why the good manufacturers include photometric information on their documentation, including candlepower distribution curves and CU tables.

Part of my review will be pointing out the lack of data about the specified fixtures and recommending several alternates by manufacturers who provide the information necessary to evaluate their products.

IALD Set To Launch CLD Credential

After five years of planning the IALD is set to begin accepting applications for the newly created Certified Lighting Designer (CLD) credential. The CLD credential is similar to the LC (Lighting Certified) credential in that it is meant to demonstrate lighting design competency. Unlike the LC, the CLD credential will be awarded based on a portfolio review that demonstrates proficiency in seven areas of professional practice rather than by passing a written test. The other difference between CLD and LC is that the CLD will only be awarded individuals with at least three years of experience as a lead designer. This means that some people who have earned an LC (sales reps, for example) will not be eligible for the CLD.

Why does this matter? First, the LC credential carries some weight, mainly because since 2009 the GSA has required the lead lighting designer on U.S. government projects to be Lighting Certified. However, many designers are unhappy that people who aren’t practicing lighting designers can hold an LC credential. By limiting the CLD to working designers, the IALD hopes it will be seen as attesting to the holder’s skills as a lighting designer, not just their knowledge about lighting in general.

Second, lighting design is in some ways the redheaded stepchild of the architectural design professions. Lighting design is not licensed, meaning that anyone can say they’re a lighting designer. As a result, lighting design is provided by electrical engineers, architects, interior designers, sales people, and manufacturers who have widely varying education and training, and with widely varying degrees of success. The CLD could be a means of identifying who is a lighting designer and who is not.

The key to the success of this project is public awareness. If the IALD only talks about CLD to the lighting design community it will be nothing more than letters following a person’s name on their business card. Building owners and other clients have to understand the value that professional lighting designers can bring to a project, and have to insist that the design team includes a professional lighting designer. Architects and interior designers have to understand the role of a lighting designer and be willing to tell their clients that a professional lighting designer is an important part of the design team who is worth the additional fee. If, through the CLD, the IALD is able to raise awareness about lighting design in those who can benefit from it, it will have been well worth the effort.

Starting A New Design

I’m between classes at Pratt, so I’ll have to be brief. It’s the time in the semester when my students start to feel overwhelmed. After talking about vision, light, psychology, design, lamps, color, and light fixtures they’re about to start working on designing projects for class. The most common question is something like, “How can I possibly organize all of this information and start to make meaningful design decisions? I need to pick a light fixture, then I need to pick a lamp for that fixture, then I need to lay out the fixtures to arrive at the lighting that I want, right?”

Wrong! A lighting design doesn’t come from the lighting fixture, so design decisions shouldn’t start there. In a push-me-pull-you kind of way the first questions are always about the end result. Rather than choose a fixture and follow the light down into the room, what we need to do is understand the lighting requirements and follow the light up to the lamp and luminaire. How do you want the space to look and feel? What lighting techniques can help achieve that look? Is there an overarching thematic element that needs to be included? How can we express the lighting goals in terms like intensity, color, and distribution? The answers to those questions should start to lead the designer to requirements for the fixture/lamp combination, and to the number of fixture types required to implement the design.

I explain that it’s not always a linear process, and that a certain amount of trial and error is part of any design. “Does this fixture give me the distribution and intensity I need?” isn’t always a yes/no question that can be answered by looking at a cut sheet. Sections may have to be studied, calculations run, different lamps and accessories considered, always with the end goal in mind.

Yes it’s hard. So hard, in fact, that some people spend several years studying light and design at the college level before getting their first job, only to discover that there’s so much more to learn! If you have a passion for light and design, though, trust me it’s worth it.

Happy International Year of Light 2015

The United Nations has proclaimed that 2015 is the International Year of Light and Light Based Technologies, also referred to as IYL 2015. 2015 is the anniversary of quite a few notable discoveries about light. The UN resolution recognizes “the works on optics by Ibn Al-Haytham in 1015, the notion of light as a wave proposed by Fresnel in 1815, the electromagnetic theory of light propagation proposed by Maxwell in 1865, Einstein’s theory of the photoelectric effect in 1905 and of the embedding of light in cosmology through general relativity in 1915, the discovery of the cosmic microwave background by Penzias and Wilson, and Kao’s achievements concerning the transmission of light in fibers for optical communication, both in 1965.”

By focusing on the topic of light science and its applications, the UN hopes to raise global awareness about how light-based technologies promote sustainable development and provide solutions to challenges in energy, education, agriculture and health. It’s an exciting idea, and I hope that we see a lot of activity surrounding light and lighting design in the profession, allied professions, and the media. It’s a great opportunity for the IALD, IES, manufacturers, etc. to raise their profile, raise the profile of lighting design, and educate people about the advantages of well designed lighting. Unfortunately, as of today very few activities have been announced and none of them are activities or events related to lighting in the built environment (not counting annual events, such as LightFair, that would happen anyway). If you have any contacts within these organizations, urge them to take advantage of this special year.