Museum Lighting 101

Museum Lighting 101


– music – – applause – So, I felt a little silly that you traveled all this way to see the Smithsonian and I’m gonna put you in a conference room, but it’s really the quickest way I can communicate a lot of information And, I know that there’s all kinds of levels of lighting students here – and professors – it’s gonna scale back and forth. So, some stuff is gonna go over your head, most of it will not. We’re gonna start with an architectural history of the building and then move on to the specifics of, well, museum lighting design, for sure but also how I see light and a potential method for the heuristics of explaining what light is. Hey, that’s our building. Big purple building. We have the White House, the Capitol, and our building. These are the three oldest buildings in Washington, D.C. Here’s another view of our building. So, we are the, this was the Old Patent Office, commissioned in 1836, by Andrew Jackson. This image of the building is from an actual patent issued to a Thomas A. Edison. From Menlo Park, New Jersey. As you see, this one is for the telephone, because I could not find the patent for the light bulb, but this group could. So, if anybody finds it, and if it has an image of our building on it, please send it to me. This was issued in 1882. One of the interesting things is, we finished a large renovation of our building, oh, 2006? When this was taken in 1882, it was in the middle of an 8-year period of renovation, and as I was first putting this talk together, it became very aware to me that I am one of a long line of lighting designers that have been figuring out how to bring light to this particular building. First, with an incandescent light, and much more recently, spending a lot more time looking at LEDs and more energy-efficient sources. So we opened in 2006. That wasn’t a time to look, well, I did look at more energy-efficient sources, I had no success, so we’re really locked into incandescents. I’m working on other museum designs now, and it’s a very difficult choice of exactly what lighting technology to put into today’s museums because LEDs are still in transition. And our story starts with the architects. This is–well, architect–is Robert Stuart Mills, if there’s a hero of this story, that’s him. See him there with his lovely wife. One of the interesting things about our building, 1836 we were commissioned. That precedes photography and artificial lighting systems, so as I take you through this architectural tour for the next ten or fifteen minutes, you’re going to get a history of both, of how people brought light to museums in various methods, and you’re going to see some early photography. Robert Stuart Mills started his career in the study of Thomas Jefferson. Spent several years studying in his library, Jefferson recommended him to the great American architect, Latrobe. Went up to Philadelphia and worked with Latrobe, Mills actually billed himself as the first American-born architect. Whether he was, I don’t know, but he billed himself that way, and he was certainly very early. And he built a building. He was given a commission for our building, he was giving a gentleman’s drawn, a loose drawing of a building that was based on the Parthenon. The building from the original was supposed to be four wings, again, loosely based on the Parthenon, and this is the first wing he built. The first wing he built. This from a daguerreotype in 1856, and I like this image because you can see it as a separate structure. You can see the resemblance to the Parthenon. Mills, like Latrobe, were looking to find a specifically American form of architecture. They looked to the past, but having married that neo classical past to their contemporary present, and they were bringing both sensibilities at the same time, and you can see the portico actually resembles the actual Parthenon, and that’s my mom. Always give a shout-out to mom. Building has three main floors. The floors get grander as you go up. The top floor, when it was completed, was called the National Gallery by Congress. It housed the Declaration of Independence, our early collections, largely of copies of American, of European painters. George Washington’s sword. Great double staircase allowed light to enter. The building is about 60 feet long, allowing light to penetrate, and I’ll show you that in another view. The purpose of the building was, while it housed national collections until we opened the Smithsonian, the purpose of the building was as the patent office of the United States. It was also housed the actual patent models. In 1836, not only was our building commissioned, but the patent laws were ensconced that made, when issued a patent, in order to get a patent, you also had to present a patent model. The viewing of these patent models was a very popular thing, straight through the 20th century, into the 20th century, and people would come to our building to be inspired by these models. Our building was like the Wired, or Scientific American of its day, that people would see what people were working on so ideas could generate from then, and those patent laws really were quite effective at spurring innovation, protecting the patent for a limited amount of time, but not so long that it would squash innovation. This is a good time. So, like I said, I’m one of many lighting designers to have brought light to this space. Those are our great architects, the beginning. The architect’s lighting designer for the renovation was Claude Engles, I mentioned Alex Cooper, who was the lighting designer for Portrait Gallery. He came by to, he started just about the time we were finishing construction. The Courtyard’s lighting designer was George Sexton, and then our electrical contractor was Singleton Electric. Civil War breaks out, what display cases that had help patent models were cleared and this building became a Civil War hospital. Interestingly enough, Clara Barton got her start as a government employee working in our building. She was the first woman to get paid general scale as a government employee. Walt Whitman had a job in our building, I think working for the Indian, Bureau of Indian Affairs. He tended civil war wounded, working in our building. You can see the patent models along with the soldiers being quartered. Lincoln’s second inauguration happened in our building. Months after the 14th amendment, 13th amendment or 14th? I just saw Lincoln. Never saw Lincoln? You have to go see Lincoln, it’s great. “With malice toward none, with charity towards all,” were Lincoln’s great words the day of the second inauguration. These are gas jets. They were brought into the gallery just for the Lincoln, the inauguration. This room was not designed by Robert Mills. Some people had said some bad things about Robert Mills. They had called him a bad architect in one way or another, there’s a commission to decide whether he was all that. Thomas U. Walter, who was the architect of the, became the architect of the Capitol, the first president of the AIA, was the head of that commission, and he had some bad things to say about Robert Mills. Next thing you know, Thomas U. Walter is the architect of the building and he designed this room, and while he had respect for what Mills had done, he wanted grander spaces without columns. The problem with that is that Mills specialized in fireproof construction. This used this new “I-Beam” technology with a wood roof. Wood isn’t fireproof. Within several decades, Walter’s wings burned. Mills’ wings did not. 1877, we had the great fire, the fire in our patent office. And, U. Walter’s wings burned down, especially the third floor. We rebuilt it. The German architect, Adolf Cluss, well, German-American architect Adolf Cluss, rebuilt it in this high Victorian style. It’s many years later, the styles have changed. We’ve gone from neoclassicism to Victorian, and you can see the display container. This is made to display patent models. I love this rendering. If you’re familiar with Washington, D.C. architecture, Mills designed 4 great buildings in Washington, D.C. If you look across the street, you’ll see a lovely little post office building, the Treasury building is a massive building next to the White House, and the Washington Monument. Those are the four great Mills buildings in Washington, D.C. Adolf Cluss did the Smithsonian’s Art and Architecture building, which is right next to the Castle. It’s a great, really fun building. And Eastern Market, are two other examples of his work. Time moves on. We’ve become less of a display space and more of a patent space. This is becomes our patent library, the same gallery, so we’re kind of taking a history of our West Wing over time. Every 20, 30 years, you change the lighting fixtures, then. Time moves on. And you can see the patents, the patent libraries from various countries. When L’Enfant set out the plan for Washington, D.C., on our spot he had planned a Parthenon for America’s great heroes. In the early 19th century, we did not need a Parthenon, we did not need a museum, we needed a patent office. In 1950s, 1960s, is a much more appropriate time, and they were, this building was slated for destruction, and it was saved to house the collection of fine art for the Smithsonian, and a smaller part of the building for the National Portrait Gallery, fulfilling L’Enfant’s vision for the, a place to visit America’s great heroes with the Portrait Gallery. This room went from a patent library and a model hall to our actual library. It looks like a big old 19th century library. In 2000, we closed for a period of 6 years and did a massive renovation. We took the thing down to its bones. We opened up fire, fireplaces. You could smell the wood smoke from the 19th century, as we opened up these chases. These chases would eventually house HVAC. And we rebuilt it, and this is what it looks like today. And that’s a good place to start talking about light. So we’re going to walk down one of these aisles, and this is kind of exhibit lighting design at its simplest. What we just have is a series of wall washes. This is open storage. This is the Luce Center for American Art, and this is an opportunity for us to put 3,000, over 3,000 works of art. In the rest of the museum, hung in a much more traditional way, we have about a thousand works of art, so this is high-density storage. And I’ll show you a little about our lighting design. We designed these fixtures so that you could open the glass doors, and the MR-16s would be small enough. This is a wall-washer. The purpose, and it’s the same thing that, well, actually we only have one or two here. The purpose of the wall-washer that’s open to the wall, so you can get as much field this way, but it’s closed to the viewer. So, so much of what we’re trying to do is baffle the light, but we don’t want to baffle the light off of the wall, so this is how we end up with this shape. I stole a detail, I designed this fixture in collaboration with Zumtobel, and I stole this black edge. That was a detail that a gentleman named Edison Price had put into his last line of fixtures, and Edison Price was the great fixture designer who developed a vocabulary for how to light flat walls without glare, and that was his distinctive innovation and how he had spent his life. To light space as flatly as possible, a wall, a plane, as flatly as possible, but you hide the lighting source. And then this is a deeper baffle for what he called, “object lights.” MR-16s are, of course, very glarey, and we have this series of lenses to shape the beams. And this is what you get, where one light runs out, you put the next light. As simple as can be. So that’s basically the story of our West Wing. And you can see as this is kind of a little history of our building, we started with the South Wing, finished in 1842, which is where we’re going to go to next. The building is about 60 feet long. That interior courtyard allows light to penetrate deeply into the building from all axes. There’s over 500, 545 windows in our building? That was the source of light when it was constructed. Oh, and you can see, this is an old picture, you can see our two giant helms. So we’re going to move onto the South Wing. This is the oldest wing, and it’s interesting they had to talk about daylight and to kind of re-imagine what it would have been like. I had a friend who, a lighting designer, who called a building a darkness generator, and lighting this building with daylight, the highlights would have been much higher, and the daylights would have been much lower. A lot more kuroshiro than the very flat lighting that we typically get in our interior spaces now, and here’s a photograph here showing exactly that. This incredibly bright light? That’s the north window. The brightest lights are actually coming in from the south. ISO contrast ratios? Not so much. Time moves on, and this space, our building was the first building in, the first government building to receive gas light, and with gas light, we get an artificial lighting system. In 1852, we started converting over, and we took what was originally a gas lighting fixture, the architects sent it off to Rambusch Lighting, who produced, based on those lamps, an electric replica. First we have to renovate the building, and what you see here is the old channeling. The first renovation of our building for the museum was done in the 1960s, and they did a lot of channeling of the plaster and brick. That’s one technique. You’re going to see a different technique for what we did for the renovation of our building. And when we finished it up, it looks like this. With a great double staircase. He got in a lot of trouble for that staircase. That was one of the complaints, it’s extraordinary, it’s like the architectural jewel of the building, but some, they said, ‘oh, that wasn’t part of the specification that Congress asked,’ so that was the pretense they used for kicking him off the job. Oh, that was Robert Stuart Mills. So that’s our South Wing, let’s move on to the East Wing, and we’ll talk a little more about exhibit lighting design. This is another Rober Stuart Mills’ wing. I like this picture. You see the gas light flume, you see displays which I, seeing as it’s so long ago, and you see actually these are shutters, which would be daylight control. Electric light, it wasn’t very pretty when they started off. You see this wonderful deathtrap wiring. We had the challenge of how do you turn these rooms that are roughly 20 by 20 square, into galleries, and we wanted to think outside the box, we didn’t want to just stick lighting tracks back up on the ceiling with ugly fixtures, basically. Track fixtures don’t say anything about the architecture, they’re not particularly attractive, and we didn’t just want to assume that would be the answer, so we thought about it and thought about it. We looked at these rooms, we tried actually dropping pendants. The Europeans are really good at separating what’s historic from what is contemporary, and setting them up, so we did tests where we had pendants. What we found was it didn’t work. It bisects that arch, and as nice as our ceilings are, it’s the arch that you see, which expresses the architecture, and as soon as you drop that pendent, you’re really disrupting the architecture, more than sticking the lighting track on the ceiling, which is eventually what we did. So we tried not to do it, but, and that’s largely what we’re going to be talking about today. I had a friend who addressed a letter to me once to the “department of track lighting,” so this is track lighting 101, folks, and we use track lighting because it’s great. It allows us a phenomenal amount of control and flexibility. Where to stick the track was something of an issue. The closer you get it to the wall, we have these double-groin vaults that you see right above our heads. The closer you get to the wall, the more linear feet of track, the more track lights I can put up. The closer to the center, the better are the lighting angles. So, I laid out each track in each room, to really maximize that relationship, and to balance those two properties. How to design light. This comes from the theatrical lighting director, Max Reinhardt, from the late 19th century, 20th, in the early 20th century. And he said how you design light is you put light where you want it, and you take the light away where you don’t want it. And that’s the essence of controlling light. Our building is made of masonry. This place is a solid brick. It was built to be a fireproof building. There’s no plenums. How you run wire? How do you get all that electrical stuff in a building with no plenums? The first thing you do, is bring in bulldozers in, you pull up your marble floors, and you excavate all the rubble fill in those cavities. We then fill the floors with every stick of wire and conduit we thought we would ever need in the future. We then filled those areas back in with a flow-fill concrete. The electricians core-drilled, they located where all those junction boxes needed to be for all of our lighting shock, core-drilled the building, and then ran the wire in the floor above. And then, the finished ceiling. The plasterer’s union actually brought in cameras to photograph how you get a smooth plaster layer. They had to reinvent the 19th century techniques to redo our buildings. And this is what you see are these pull-wires with the junction boxes, and finally, the lighting track installed. Daylight was quite a trick, and there’s so much light coming into our building that we actually had to do several layers of film and scrim to reduce the amount of light, and as we tour through the building, I’ll talk a little more about that. What’s nice about this image is this window had broken, and it’s, the window film hadn’t quite, hadn’t gone back on yet, so you can see the difference between window film and no window film. And that takes us to the second part of our talk. So that’s the history of our building, and this is the controllable properties of light, and I get this from, originally, the first time I saw a list like this, was from Stanley McCandless, who’s one of the first teachers of theatrical lighting in the 1920s. How many people have seen this list? Are familiar with describing light like this? The great lighting designer, Tharon Musser, talked about this list and she taught her students, “you open your eyes, and you see.” This is how she would describe the light that she sees, and I’m, I’m actually giving a talk at LIGHTFAIR with Naomi Miller, where we’re going to take this, these five qualities, these five, as this is the five things as lighting designers we can control with light. They don’t, these aren’t engineering terms, these are design or art terms. They’re analogous to Aristotle’s poetics, politics of drama, where the elements of design– what are they, art, the elements of art are line, form, shape, color, texture– as lighting designers, I put forth this, this list of five is what we get, and it’s the way I like thinking about light and talking about light, and if they’re holes to be drilled in this, if you’d be so kind, please email me. I’m going to leave my email at the end of this, you know me, tell me, drill holes in this, because I’m really excited about the possibility for both you, of course, and the greater public to think and see light in a better, deeper way. So let’s use the light you see me under, and go through this list. Light has distribution. Is it a spotlight, is it a flood light? Is it a single light, or is it an array of different lights painted throughout the building? So you go from the single light to multiple lights, and how are they painting the space with light? All that is distribution. The texture of light. Is it a flat light, or is it a dappled light? These aren’t small terms, these are big terms talking about big concepts of controllability. I’ve got this distribution of light, and you can see the fall off here. The field and the beam. Light is, of the five controllable properties, four of them are about the lightbulb, and one is about where you put it, and that’s angle. Where are you going to put the lights, and that’s going to affect distribution, so the angle, the longer the angle, the longer the shadow, the bigger the light, the farther away, but that angle’s going to decide the ridges under my eyes. How flat, or how dimensional I look. I spend more time with these first two, choosing the right distribution and the right angle. Intensity, how bright is the light? Fair enough. The color of the light. So it’s looking kind of white-ish yellow at this point? If you look at the window, and take a minute, or take a few seconds, and stare out the window. Do I turn yellow? Do you see the yellowness of the light now? So, whatever the colors are, these aren’t good things, these aren’t bad things, this is just what we get to control as designers, or at least that’s the proposition I’m putting forwards. Lastly is movement. Daylight, what is the solar path of the light? We’ve got CX-10, we’ve got Martin Moving Fixtures. One of the things I talk about most with movement is flicker, and since i’m looking at a lot of LED sources, some of them flicker, and we spend so long as a lighting design community, getting flicker out of the built environment by pulling magnetic transformers out of our fluorescents, I am determined not to re–have flicker re-enter our built environment with bad control of LED lighting. I’m gonna go through in actually some detail, this list again. So, and kind of drill down. We start with distribution, and that’s going to be the deepest I’m going to go into any of these. So it’s two–this image was taken about 1999, I have to start picking lighting fixtures for the building, what do I pick? And it’s really, at that time, really came down to how you stick a filament in a parabola. Within, well, the incandescent side, I’m dealing with parabolas, and I’ve got a filament in the center, at the conjugal focal point. All the rays that are coming off the reflector are going to go straight, so it’s really a matter of what is the size of the filament compared to the size of the reflector? The smaller the filament, the bigger the reflector, the smaller the beam of light. We’re interested in low-voltage. We’ve got low-voltage and line-voltage. Line-voltage is a big, chunky filament. Everything that doesn’t fit in that conjugal focal point is going to diverge. This was a revelation when I heard it, and I figured it’s worth repeating. So, I’ve got my smallest beam of light in my 5 and a half volt Par-36, which is– and if I take the same scaled reflector, with a larger filament, you can see they’ve gotten about the same size spots, but this is all that crap that’s outside of the conjugal focal point that spreads light everywhere. So, same size reflector, same size lamp, tight spot. This makes a much better flood, so I don’t want to–so using those Par-36’s as flood as flood lights, they make terrible flood lights. But they do pretty well as spot lights. And vice-versa. Lines–I typically use line voltage for floods, low voltage for spots. Once we get to LED, the capulus changes a little bit, and now, I don’t have a sing–typically, I don’t have a single LED in a focal point. Sometimes yes, but sometimes no. Just as often, I’ve got arrays of LEDs, and then it becomes the size of the LED fitting into an optic and fitting into a reflector. If there’s a reflector. And I’m very interested in that Cree XP-E chips are smaller than Cree XP-G chips. The XP-E make better spotlights. The XP-G has better thermal management, and my LED manufacturers are balancing those different characteristics. Molly, are you around? Could you close the door please? Oh, good, why do I care? Why is all this beam spread so important to me? Let’s take a look at one particular artwork by Paul Manship, “Flight of Europa.” It’s got a bunch of lights on it. I’ve got a light coming in to the bull, I’ve got a light from a low angle to make it more sparkly, and I’ve got one light on Europa. I take that light, I slide it off to the left. What I’m trying to do with all my art lighting is that I’m trying to match the size of the light to the size of the target. What that allows me to do is, instead of getting– if I did this with, say, line voltage light, line voltage incandescents or lamps that weren’t four degrees, that four degree 5.5 is my smallest point of light. If I were to use 8 degree lights, I’d have giant beams of light on my walls. Giant. Do you see this little slop of light on the floor? That would be a huge slop of light, which would fight, which would be highly luminous and fight for your attention. This is the only way that I know to get the artwork to be the brightest thing and not to get the lights to be the brightest thing. Let’s go in the way back machine, to the 1990s, and this is how our galleries looked before our renovations. The biggest deal was, we didn’t have baffling. The lenses sat on the outside of the units. We also had 90s issues with hair. There’s a single run of track down the center of our galleries, which, that angle of light, cast a shadow on the artwork. Spring forward to 2005, and this, our wonderful sea greens. The angle, you can see is lower, we’ve doubled the amount of track, increased the amount of space for track lights. The biggest thing we did, is we pushed the light back into the fixture and added glare control. That reduced efficacy dramatically, but it’s worth it. I think it is. I’ve, so much, I’m going to show you another picture of it. So, this is our second floor galleries, with the lenses on the front of the unit. When you put the lens on the front of the unit, the lens–the light has a much wider spread. You need less units. We doubled the amount of lights, but we cleaned up the ceiling. So I’m very interested in efficacy and very interested in doing the best exhibit lighting I can do with the least amount of connected load, but at the same time, I don’t compare to our efficacy to an office building. I compare it to Disneyland. So we’re still talking about distribution. How do I paint with light? From one light, to an array of lights. So this is our little Par 36, which these lights had a filament shield, so actually, all of the light that is coming off these lights is off of the reflector. That does a great job at getting me tighter distribution. If you don’t shield the illuminant, you get forward throw off of that illuminate, and it throws the light everywhere. This is the line voltage, and we had a series of lenses to go along with that. These are all round distribution. These lenses are all asymmetric. We developed three lenses on the job. Each one of our four thousand line voltage lights comes with three lenses, so we have total, as much control as we can over every single light. So there’s a 55 degree beam, a 55 degree lens is what we called it, a 70 degree, a wide angle, which is mainly for wall washing, the 55 degree would be for lighting a large painting or sculpture, and a 55 by 70. We almost always want asymmetry because our lights are largely round distribution and this is probably obvious to all of you. If I take a piece of paper and I shape it into a cone, I’ve got a cone. And if you bisect that cone, you get an ellipse. So, that round distribution when it hits the wall, is always going to end up as a scallop. It’s where that cone bisects the wall. So, my challenge as a museum lighting designer is how to present these rooms in a way which will help the visitors experience what is being offered, to see the historical nature of the rooms, to see the rooms for what they are, to see the artwork for what it is, and a lot of it is controlling these beams of light, so what’s actually interesting is, I’m going to go back… This is my first test of LED lighting. This back wall is LED, and this wall is incandescent. And, that was kind of the charge I was given as a designer to transition to LEDs for this museum. They were very pleased with the quality of lighting that we had, and they didn’t, they were not interested in the different color of light, they didn’t want a different color of chromaticity, they didn’t want a different color rendering. They wanted me to match the incandescent light they liked so well, and this was the first test to see that we can do anything with LED. It’s a matter of controlling the spectrum, and it doesn’t matter if it’s incandescent or LED. So my goal, for my LED conversion, is for no one to notice. And this is kind of a, the canary in the coal mine for that. So this is looking at LED. The thing is that it doesn’t matter. A museum retrofit lamp LEDs, and they basically work very similarly as the legacy incandescents. I’ve got two layers of light. I’ve got spot lights on the artwork, and I’ve got wash lights on the wall. I take the spotlights and I trim them off. Now you’re just seeing a wall wash. Those lenses, those asymmetric lenses take those scallop of light and they smooth it out, so they take something that’s a scallop this way, and you actually end up with more of what a round distribution, and that’s what it looks like without the lenses. This is the look you’ll see in galleries all over the place, but I would say it has, those scallops say nothing about the artwork, and they say nothing about the architecture, so I put my asymmetric lenses in and I smooth them out. This is gallery lighting at its most simple. It’s not bad, but if you’re going to get illuminances, higher on the artwork, you’re going to start fighting between the low reflectivity artwork, and the higher reflectivity wall, so we very carefully spotlight the artwork, matching the size of the light to the artwork. I turn the lights off, now you’re just seeing spot lighting without the wall wash, and that’s a look that you see. It’s a very dramatic look, but so much of modern art is about the relationship between the white wall and painted surface, so we want to balance those two ratios, so even though the paintings are on the wall, I’m still working with two planes of space. That’s a story of distribution, and that’s the longest story. We’ve got three, four more to go. The angle of light. Where do you put the lights? That’s going to determine whether the– the lights glare, where the shadow is from the person looking at artwork. Where is it dump? The lights cast shadow. Are those shadows going to become visual noise, as lighting designer Steven Hefferan would call it. So, we’re controlling that. This is a long corridor. We’re taking a 19th century office building and turning into a museum, so we’ve got lots of these long corridors. As soon as you take a light and aim it at any place except at the wall, it’s going to be a glare in your eyes. All that is the angle of light. Well, this is interesting, this is a great group to do this with. So this is the Lansdowne portrait of George Washington before we renovated our building. There’s two sources of glare here, and can anyone tell me what the two sources are? What’s creating the glare on this painting? So, we’ve got glare here, and glare here. The largest amount of glare is from the window behind you, and this is from the track lighting above. Typically, most of the glare problems we have in our galleries are not from the track lighting, it’s from luminous surfaces behind the visitor, whether it’s a video screen, a window, or a bright white wall. Glare from the track light only becomes an issue when the painting is significantly over your head, and then it’s just a matter of playing pool, it’s angle of incidence equals angle of reflection, and we take the lights and we shift them off to the side so, in this case, this is Alex Cooper’s lighting design. This is a Portrait Gallery piece, and he would take the lights and try to aim them from one side and dump the light so that the people standing in front of the painting don’t receive it. These are controllable properties of light, not good and bad. This is a great arts and crafts piece by William Fosdick, and in this piece, it’s wood, which is light-sensitive, with gold. My goal here was to make the gold reflective, so I used a low angle. I wanted to use glare, and that glare allowed me to light the wood at a lower level and still have it shine. Intensity, hell, intensity is easy. In a museum, it’s conservation-driven. We’ve got two main categories of light. Things are either very light-sensitive, well, three, really, moderately light sensitive, or they’re not light sensitive. If they’re not light sensitive, I get to do anything I want. Anything that went into a kiln, or saw a blow torch, is not light sensitive. Once it sees fire, there’s nothing my light energy’s going to do to it. Very light sensitive things are watercolors, textiles, largely dye-based things. The moderately sensitive is largely oil paintings. As soon as you take pigment, or even dye, and you put it into acrylic or oil, remove oxygen from the equation and things become much more light-fast. We, these values were determined not by what will damage the objects, but by what we need in order to see. And I think I–Rick, I had asked, when I would taken your class, what, where we got these values, and at thirty lux is what you told me, and I think you sent me some documentation, at thirty lux with a 50% reflective material, photopic vision kicks in. Recently, the IES, I’m the chair of the IES museum committee, and we doubled the values for visitors over 65 years, I think is the way it goes for the IES handbook and as these levels, I have a slide on that. So there’s four things that damage artwork, the four ways to look at it. It’s the intensity of the irradiance. It’s not just, we’re not photopic, it’s not human vision, it’s the absolute energy of the artwork, of the light, rather. How long is that artwork on, how many hours? What is the spectral distribution? And, what is the specific thing’s susceptibility to fading. When it comes down to it, this is, if you want to take a note, that’s it. We just do what the conservators tell us to do for the most part. What’s interesting is the five to ten footcandles is, I think a better metric. That’s pretty solid, and my experience bears that out. I really am very grateful, most of the time I’m given 5-7 footcandles for the most light-sensitive. The difference between five and seven footcandles is, that’s about 30% difference, so that’s a noticeable difference amount of light. The second is much more fuzzy, how they came up with those values, because they’re not necessarily photopically based. So, while those are our levels, that we can see at those levels, and for most reflectivities, for most materials, we can see well at those levels. If things, if the value is too dark, it becomes very difficult to see at 7 footcandles or 75 lux. I added color to this list. I think you need a little more light to see blue, depending at least on the spectrum of the light. The contrast of the details. You need more light to see 6-point than 12-point. You guys know this stuff. On the size of the details, contrast of the details is black on white paper, you need less light, if you’re seeing black on black, you need more light. And size of the object, this is a little counterintuitive. Watercolors, you are right on top of. You’re very close to a little tiny piece of artwork. You may need a little less light if you’re right on top of something than if you stand back. Seeing something that’s much larger and grander. So those are the five things that’ll determine how much light an object needs to actually see and experience it. Oh, and that’s retinal illuminance which is, we fought long and hard about raising those limits for our older populations, but all light damages artwork. Light, 400-700 nanometer light, destroys artwork, and there’s no use destroying it or damaging it, fading it, if people can’t see, so we really have, we’re always–that’s the balance we’re continually fighting. What is light? You guys know this. The only difference in museums is we’re not just looking at the psycho-physical, the lumen, we’re also looking at the absolute energies. Oh, I have a question. It’s just so great when I get to talk to a group that’s often smarter than me, I like this. For colorblind people, is the lumen the same? So my understanding is that we’ve got the tristimulus values, and they integrate into a lumen, which you see down here, do colorblind people see illuminance the same way that non-colorblind people do? It has to be different, that’s what I was thinking about in the shower this morning. Picking through the slides. So I’m dying to find out more about that. That takes us to color. It used to be really, really simple. I had incandescent light. I didn’t have a choice. In order to get the distribution of light I wanted, incandescent was the only thing that would sit into a parabola tightly enough to get me that 4 degree lamp. It still actually is. I can’t get a 4 degree beam in anything but incandescent. If you know anything, please call me. With the advent of LED, I all of a sudden have, not only, I’ve got control over the spectrum in a total way, which made me learn about color in a way that I simply didn’t have to know when I was limited to incandescent, and I spent much of my last two years learning about color. At its most simple, I’m looking at three things. The chromaticity, what is the apparent color of the light? Is it warm, is it cool, is it blue, is it purple? And color rendering. How does any one light let us see a broad range of colors? Right along with that, museums have a third factor, which is different spectrums would damage artworks in different ways. Welcome to my shop. I didn’t clean up for you guys, you’re going to get to see it later in the day, and what I have is two color checkers, two targets sitting on the wall on little music stands, and lights pointed at them, and from that I can assess those two main qualities. On the wall, which is kind of white-ish, I can see the chromaticity, what is the color of the light? And from the color checker, I can see, does that particular light illuminate a broad range of colors. I have two of them, so I can test a reference and a test. I can compare one LED against another LED, or incandescent against an LED. The two samples have to be the same color, chromaticity, they have to be the same illuminance. To have a fair comparison. I, evaluating lights of different chromaticity is a level of complexity which is, it’s a new level of complexity, and it’s much more difficult to do. You basically, how many people are familiar with CIE charts? So, what this basically is showing, the color of light in a color space and how basically incandescent light changes from red through blue. This is, there’s two main metrics we’re looking at off this chart, CCT, or Color Temperature, and DUV. I’m going to jump to a different color space, that was 1931, this is 1976, and you know because we’ve now gone to U and V, and Kelvin temperature, describes a light from yellow through blue. The only lighting source that sits on this black body locus, this Planckian locus, is incandescent light. Daylight is above the locus. How many people have heard of DUV as a metric? Oh, this is great. So, I’ve been getting to work with the Department of Energy for several years, especially Naomi Miller, and her team, great lighting designer, and a great writer of lighting design books, and that team brought this metric, DUV. How many people have heard of Kelvin temperature? A lot more. So DUV is describing whether the light is pink or green. The only thing that Kelvin temperature tells you is yellow to blue. So, if it’s a negative DUV, it’s pink. If it’s a positive DUV, it’s green. This is the black body locus, that curve, these are called isotherms, running perpendicular to the locus. We are more sensitive as humans to the pink to green shift, than we are to the Kelvin temperature shift, and if you look at NCC-78.377, which is the NC standard for LEDs, you will not see, you will see that they weight Kelvin temperature shift differently than DUV shift. This is great. DUV is our friend, and we should insist that manufacturers give us that data. Is that pretty much, did I miss anything there, Rick? Rick: I haven’t done that much with it since I’m not much for the LEDs, so. Scott: So you’re all about daylight. There’s some daylight. So this is, in practice, this is a great artwork by Beth Lipman. This is all glass. She asked her whole community from Sheboygan, Wisconsin to craft pieces of glass, and pile them on top of this table. Literally dripping off of this table with glass. This was part of a gateway demonstration project with the Department of Energy, where I was transitioning to LED, so I got my little LEDs. I’m very concerned that each LED is going to be the same color as I line them up on the wall, so that’s my little test. Yep, pretty good. I aim them back down on the glass. This is incandescent light. Pretty bright. That’s LED. Not much of a difference. It actually got a little brighter with the LED. So, this is all chromaticity of the, apparent color of the light, so I want the lights to be the same color from lamp to lamp. I want, within the beam of light, it needs to be the same color, and over time, they need to stay the same color, and that’s the big problem with LEDs, that I’m having. Throughout the Smithsonian, we’re testing them at 7 different manufacturers of retrofit lamps, and we’re seeing color change in almost all of them. They’re not staying the same color through time. Between 4 and 6 thousand hours, we’re seeing significant color changes, from between 3 and 20 steps of change. I’m measuring that and sending that data along. If anyone’s interested, I can share that data, send me an email. Color rendering. Different illuminants are going to render in different ways. This is from Roy Berns’ great book on color. [Saltzman, Goodmeyer and Saltzman]. High pressure sodium does a terrible job, you can see red and yellow. Cool fluorescent does a pretty good job. The color of light and how a light will render a broad range of colors. I look at as separate things. They’re related, but I look at them independently, and I assess them independently. I just like this list because we don’t have that many lighting sources to choose from, it’s just nice for me to see them in one place. When you look at a spectrum of light, this is interesting from a museum perspective. This tells me very little about color rendering. You can tell a little bit. You can tell the high pressure sodium isn’t going to do much for blue and, blue and real red, but you really can’t look at the color rendering aspects of a light this way, and I’ve got a short little rant, so this is, this’ll be advanced for some folks, but is nice to let it flow through you. It takes four, three things in order to see color. You need something to look at, a target, and this is our intern measuring the blue on that painting with a spectrometer, and this is the blue. This is human visual response, long medium and short wave, blue red and green, and this is light. This is a compact fluorescent with three main peaks that pretty much light up with our tristimulus response. One at a time. So we have a blue painting, the blue part of the painting in the previous image. So that’s blue. That’s a target, and we add a person to that. The human visual response, and we overlay them. So what this shows is that people can see blue. And now, I light to it, and it shows that this light has blue. It doesn’t show anything about how well we see the blue. Looking at an SPD does not tell us about color rendering. We need a metric to tell something about color rendering. We need to integrate it with, well, there’s two ways. One is, to light a colorful thing and look at it, or to use metrics, and in color rendering, metrics, indexes, is really the only internationally agreed-upon metric, and that basically takes a reference source, which is incandescent below 5 thousand Kelvin, and a test source, and compare the two. The delta, if there’s any decrease or increases or changes at all in color, that’s a demerit on CRI. So, if things get more colorful, and you’ve got a lamp, like neodymium has a low CRI, even though it makes everything look more colorful. Reference and test. This is the CQS spreadsheet, it’s a vision science tool that allows us to really dig deep into all of the color metrics, or a lot, not all, but a lot of the color metrics, including color gamut, you can actually see the delta of how things are getting more and less saturated, if anybody would like to get a copy of this, I’m sure your university has this available, or I can send you a copy. It’s a wonderful spreadsheet, and I learned color science through digging into this spreadsheet. This is the takeaway, for me at least, the simplest way that I look at color rendering. So this is some real-world examples, the painting that we saw earlier, the “Aurora Borealis,” I went in and I started playing with this stuff, I’m going to put different lights on a painting and see how it actually looks. Well in this painting, I saw very little difference between these three lighting sources. Halogen, 2700, kind of moderate CRI. 3000K LED, little wash. They’re all pretty much the same. I started looking for a painting with a lot more blue in the sky. The deal with blue, and what I get from Wendy Davis and Yoshi Ohno from NIST was that any chromaticity, and this is where color rendering and chromaticity kind of meet. Any color, any chromaticity, any Kelvin temperature below 3500, you’re going to see less blue in a profound way. I used 2700 Kelvin lights, and you see blue pretty well. With a blue sky painting, you definitely see more blue at 3000 Kelvin or 3500 Kelvin. Whether that becomes a strong enough argument to move towards that, is a good questions, but it was a small but, but noticeable difference. A little more depth out of the higher Kelvin temperature light. I was really interested in, I had seen high color temperature, 4 and 5 thousand Kelvin, lamps on diamonds, and they looked fabulous, so I was interested in trying it, so I went down to Natural History, to Virginia, who you’ll be spending some of the afternoon with, down at Natural History, with, and we did some tests, and I don’t know that this is a fair test. Seeing the two different color temperatures right next to each other, but it was really interesting to try, to take some lamps, go out there, and start playing with it, and what we saw was, I thought this was going to be a slam dunk that the higher chromaticity would light these gems much better, and it wasn’t a slam dunk. I find the choice of Kelvin temperature, of chromaticity, of DUV and Kelvin temperature, to be a personal aesthetic choice. They work out with my curator, with your designers, with your architect. There’s some very opinionative people who will say daylight, or one chromaticity or another chromaticity, I find it an aesthetic choice, is where it comes down, for me, after spending a lot of time staring at these lights. Last controllable property that I’m going to talk about is movement, which is, like I said, I’m largely looking at flicker. Sylvania provided old flicker checkers. These were made to determine if you had a magnetic transformer in your fluorescents, and I assess flicker in my LEDs. And, if you see a hex pattern, it shows flicker. So this is the controllable property of light. You’ve got distribution, what’s your beam spread, how you’re going to paint with light. Angle, where you’re going to put the light? Intensity, how bright is it? Color, and movement. Oh, this is Louis Burgess. I am able to sit here and talk to you because this gentleman is out there making the museum look good today. We have ten thousand focusable lighting fixtures in our building, all of them need to be precisely aimed. My lighting design is as good as bad as Louis is at aiming the lights, and thank goodness, he is very good, and the museum looks because of Mr. Louis Burgess’ help, and really keen eye. This section’s going to go fast, I just wanted to give some examples of what we just talked about. We’re going to see a lot more when we tour our galleries. I start all of my designs by looking at a thing and going, “well, why should I care about it?” Artwork can be hard to look at, and figuring out why I care is important if I want my visitors to care. What is significant, why is that thing here. What is interesting about it? And spend the time to figure it out. So, modern art is often hard, so I like starting with a difficult example. So you’ve got this wonderful red painting. It’s red. This is one of the most glorious red things you’ll ever see in your entire life. The artist put this little bit of green orb in the middle, so the red looks more red. This is a fabulous amount of red, and your lighting source that you put on it, needs to render that red in order for you to see it. Very few artworks are actually about red, which is what incandescent light is so good at. This is one of the few ones you’ll see. I also have to get that relationship between that white wall and the red, right so you can see this thing and it vibrates in just the right way. This is a color field painting, and it’s about vibration, it’s about seeing these things sing with a certain harmony. I call this the cross-eyed metric, so this painting was made to make you go cross-eyed. If it’s not vibrating, and those dots aren’t vibrating, it doesn’t have the right amount of light in the right type of lighting. This is boxes by Joseph Cornell, this great sculptor, who would take these little boxes about this big, and he’d create entire worlds in these little boxes, and you’ll see these in museums around. If you only light them from above, the entire top of the box goes dark. So, this is the label edge. We remove the label edge, and you see fiber optics. That’s lighting the top half of the box, so this is what the box looks like without the fiber optic, and I add the fiber optic back in. Another example, this is Joseph Cornell, of Andromeda. I saw this piece, this is a column standing in three dimensions, this is a chain that hangs in the middle of the box. The chain casts a shadow. I knew as a lighting designer I needed to place that shadow some place specific. I’ve got a light from above, and a light from below. I line up the two lights so they cast a single shadow. I then put the shadow in the pretty girl’s hand. I then talk to my curator, and I find out that it’s about Andromeda, who I didn’t know the story of, that she was released into the heavens by Zeus, and that she’s not holding onto the chain, she’s being released from the chain, so I moved the shadow, and now it looks like she’s reaching for the chain. Where the shadow lays helps Joseph Cornell tell the story of the artwork. Third time’s about the best I could do. The fingertips, like almost as if she’s being released. I don’t know if I’m informing the artwork, but at least I’m not screwing it up. For my last example, this is a great example, I’m…Mark Newport is the artist. He’s a fiber artist, and what he did is he took superhero costumes, and he knitted them. And they, they stretch out because they’re knitted, and he made little cartoons of people that are in need of help, so he has to knit really fast to get his costume ready so he can save the world. They asked me to project with frame projectors, zaps and pows, but I saw this work and his cartoons informed that it was somewhat about emasculation, and there’s a strong feminist component to a lot of textile arts, and I don’t know that he’s bouncing off of that or not, but he also shows himself as kind of middle aged with a big tire around his belly, and I decided that if I’m going to put, it’s not pow, it’s more like zap, and his forms are being splat, and he had this like wonderful, he put the bedroom, like he’s a child, so I kind of put a headboard on it. This had a dual purpose. First it contextualizes the artwork, also, this is incredibly light-sensitive. These works are lit at about five to seven footcandles. Lighting this provides dimension to the artwork, it brings the artwork forwards without illuminating the artwork any more than necessary. So that’s most of what I have to share with you today. [Applause] [Music]


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