 I'd like to invite you to please go ahead and begin whenever you're ready. Okay, hi everyone. I want to welcome you to today's webinar, and I'm going to go through a few slides. Remember, if you have any questions for Scott, our speaker, I will pay attention to them, and I will put them someplace where we can do them at the end of this presentation. And if we don't have enough time to answer all the questions, I will make sure we get written answers, and I will post them along with the recording. So we'll start. We have a dozen of our past webinars now have Spanish subtitles, and you will see these. You can find them on our website by searching for Spanish or espanol. And there'll be a red button, like the one you see here, and you can press on that, and it'll take you to our YouTube channel, and you can choose Spanish subtitles. We're real pleased that we were able to do that. If you have questions concerning care of your collections, you can always post them at the Connecting to Collections Care Community. And we have conservator monitors that will provide reliable help and guidance quickly for helping you take care of your collection. And you can keep up with our offerings on Facebook. If you have suggestions or problems, you can now contact Robin Kilgo. She's taking over my position. I'm retiring, and we have two webinars coming up, one in two weeks on insurance, and one on caring for clocks in January. So go ahead and look for those, and we will turn this over to Scott. Scott, go ahead. Hello. Hi. And thank you, Susan, and thank you for all your service. And we will miss you, and I'm really grateful to be here today and to be part of Connecting to Collections Care. And especially on this special day, you're a very last webinar. So thank you. We're here to talk to you about how to change a light bulb, LED lighting for museums. I'm going to kick it off talking about art. And one of my favorite exhibits that I've ever lit, which was at the Renwick Gallery, the exhibit for Lino Tigliapetra, the great Venetian glass blower. He was born in the early 30s. He became a master glass blower by the time he was 25. He started working in the Venetian glass factories when he was around 12. And this is a retrospective we did at the Renwick a few years ago, under work light. And I'll show you kind of what we're doing here, because whether you're working with incandescent LED, whatever you're working with sunlight, how light, this very energy that we need to see will allow us to see better and clearer and really tell the story of the materials that we're sharing with our public. And I think that, as you can see, that makes quite a difference. So my experience with teaching people about LED lighting is that it's really teaching about lighting. And that if you have a good handle on how to do exhibit lighting, you're going to be great at switching to LED. If you're struggling with your existing lighting design now, it's only going to get harder as you switch. So I wanted to show you these extraordinary vessels that Lino crafted and I lit to show you what we're trying to do with light. We're trying to inspire, wonder, and bring everything we can from the materials we have on view and use all the techniques of lighting to help you do that. I wanted to kick it off with all the lighting sources. So this is a complete list of every lighting sources. I wanted to start here because it was worth noting that while we end with LED at the bottom of the list, that how did we get here? Of course, we start with sunlight. And it's a perfectly great lighting source. I'm not going to tell anybody that they can't use sunlight in the galleries, despite it being very hard to turn off and used for things like light sensitive materials, where it's hard to just turn off and control the intensity. Incandescent's been great. And actually museums are one of the last big commercial buildings to still be using incandescent. Most other commercial applications, you were using either fluorescent or HID because there was so much more energy efficient. But incandescent's been so great. The color is good enough. It lasts long enough. And the main thing is that it allows us to create a very good spotlight. But incandescent, for the sake, is done. How do I forward the slide? There we go. And fluorescent's okay. Unfortunately, the sources are too big. They're difficult to control. The color is variable. It's not great. So fluorescent never had a great use in museums. And it's used as fading. HID, along with fluorescent, both have a lot of mercury. And that kind of precludes it. HID, you'll find a lot of your big box stores and highways. And even that's being supplanted by LED in this time. And that leaves us with LED, which we're going to be spending much the next hour talking about. Ah, so back in the day when I was testing lots of LEDs, this was my test bed, lots of LEDs here. Wow, where do we start? How do we pick an LED? LEDs seem to be all over the marketplace. There's so many choices. Today, I'm going to teach you more and more about the techniques that I use to determine what's good from what's bad so you can make some better selections on her. And this is how I do it. These are the controllable qualities of light. This list of five things is everything that I can control about light. I want to see how much light. Actually, I'll just slide through this. Hold on. We go here, here. Ah, there we go. Quantity is how much light. Distribution is what is the composition of the light. Is it a spotlight? Is it a floodlight? And then how do I take these combinations of spotlights and floodlights, dozens or hundreds or even thousands of them, and use them to paint light around the exhibit? So we're going to put the light where we want it, take it away where we don't, and literally paint the galleries with light. That's distribution. Spectrum. The color of light and how the spectrum that creates that color impacts the appearance of the things on view. Movement. Does the light move? Do the people move? So the light could be moving because of the solar day, the sun going across the sky, or a candle flicker, or a moving light. There's a whole range of ways that light can move. And lastly, angle, which is where do we put the light? Where does the light come from? So we're going to kick it off with, we're going to go through each one of those properties one at a time. And if you've seen any of my other talks, I really like using those five controllable properties as an organizational tool because it's really a complete list, and every talk is different even though I use that as an organizational tool. I want to spend a brief period of time on the typical lighting requirements because they're so important that we use the smallest quantities of light of 50 to 75 lux in the most light-sensitive materials. We're basically using the smallest amount of light we can to see the things that are going to fade the fastest. And for things that are more durable, say oil paintings, we can use a more optimal quantity of light. And for things that aren't light-sensitive at all, anything that had seen fire like ceramics or glass, there's no limit because light's not going to do anything to it. What's interesting about this list for LEDs is they're all reasonably low lighting levels, which now LEDs can be quite bright and actually bright enough for almost any application. But back in the day, it was a lot more difficult. So the reasonably low quantities of LED allowed us to succeed in LEDs in the early days and still to save energy by using smaller quantities of light. So I wanted to get into some of the metrics. And when you're choosing lighting sources, you may be looking at catalogs in the back of packages and they're going to use all kinds of units and fancy technological names. And I wanted to go through them so you would be prepared to know what they are. And let's start with the lumen. Let's say we take a light bulb. What a lumen is is how a lighting source can throw light in all directions. What is the potential of that lighting source to create light? Now, the lumen is actually a psychophysical unit. It's what's integrated with a standard person, standard observer. This was done in the 20s and 30s and they actually developed the lumen. What we found was that humans have a tendency to be most sensitive to kind of this structure, this green-yellow light. So it's largely a measure of green-yellow light. So what is illuminance? Illuminance is lumen per square area, whether it's a foot or a meter, imperial or metric. So let's say we introduce an object, let's say a brick wall. And how much light is hitting that square area? This is the psychophysical quantity that's hitting the wall. It doesn't tell you anything about how much light is bouncing off. So illuminance is what we use to preserve our artworks. It's what we use to lend each other's objects so we have a certain idea of a rate of damage, but it really doesn't tell us but a little bit about the rate of damage or how bright things are. A better metric for how bright things are is luminance. And we take the brick wall away, let's say we introduce an eye. The amount of light heading, if this is lumen per steradian, which is lumen per solid angle, let's say heading in the direction of someone's eye, that's luminance, or luminance intensity, which is candelas is the metric for luminance. Candelas per meter squared would give you a really good idea of how bright something is. The other use for luminance that you'll see is something called center beam candle power. And this you'll see listed on your packages, and I'll show you an example in a second. And this is another really valuable use of this candela metric. So let's say we take a spotlight, it's a 40-degree spotlight and this is a 40-degree angle, and my lighting source is 1500 lumens. Let's say that thing produces 3000 candela. If I pack a titer with a 25-degree beam, I'll end up with more than twice the brightness of the light. And if I make it even a titer spot at 15 degrees, I again increase the candelas. The candelas are really useful for comparing two different light bulbs of the same beam spread. We're talking spotlight. These are the metrics that if you're looking at catalogs or packages, they're really useful. Another way is buy some sample lights, test them in your galleries. That's an absolute great and valid way. And this is the first step that a lot of people do, is they start with a catalog, but you really should be ending up in the galleries just testing stuff out. I'm going to spend another minute showing you examples of how we use these various candelas. One, these two sheets that I found, one for an incandescent lamp of eight degrees, an eight-degree spot in here, so I can highlight that. Or an LED, the incandescent is eight degrees, and the LED is nine degrees. And if you look over here, it's just CBT, that's center beam candle power. And as you see here, it's measured in candelas. And the incandescent is at $23,000 and the LED is at $24,000. And this is a pretty good match. While we're here, it's also interesting to take a look that it's 18 watts of power for the LED. And that gives us an opportunity to talk about efficacy. Oh, but first, some people try to use watts to describe how bright the light is. So they know how bright a 75-watt light bulb is, so it's interesting to associate that with lumens. There's lots of different charts out here. This one was published by Spinet, and that's pretty good. But it isn't entirely accurate. This is really highly variable. Some LEDs are more efficient than others, but it gives you a basic idea that a 100-watt light bulb, maybe 1600 lumens, I don't know. But these are out there. Results may vary, but they kind of give you a ballpark. The candela value is much more accurate than watts. Or even lumens, because the candelas lets you know exactly how the reflector and the optics and the whole thing is delivering the light. Efficacy is also great, because efficacy is going to tell you how much energy you're using and compare this light bulb to that light bulb. And if we take a look at this 18.5-watt LED, it's got an efficacy of 54 lumens per watt. And it's simply you take the lumens, you divide it by the wattage, and there you go. Now that's about a 64% savings over a 50-watt incandescent. That's okay. I mean, it's 64% savings, which is great. I often try to get 70% or 80% reduction from my incandescent loads if I can. There's lots of continuing factors. Efficacy is one of them. But one of the great things that I've enjoyed working and transitioning to LEDs is the chance to save energy, the chance to reduce pollution to the atmosphere. And it really makes it worthwhile what we're doing here. And even on your first attempt, if you save so much energy, we're going to be at this again because these things are getting more and more efficient. And efficacy should absolutely be one of the criteria you're looking at as we go along. It's also interesting to note what the benchmarks are. Today's very best LEDs are between 125 to 160 lumens per watt. Whether they... I honestly did not... I looked at this from the Department of Energy. I did not look at my class of fixtures to see if any of my fixtures are even meeting this lumen per watt category. But for the most efficient LEDs out there today, that's not uncommon. The target that the US Department of Energy is trying to reach is 200 watts per lumen. And the theoretical limit is at 255 watts per lumens to give you a scale of where we are. So that's a short description of quantity. I could literally teach a college class on each one of these five controllable properties. Distribution, in my mind, is the most important and perhaps the most misunderstood. Let's dig in. First of all, this also gives me an opportunity to talk about the LED systems themselves. So what we have on the screen here, if I cross your back, is a light bulb. This one looks like a shower head. These replacement light bulbs can look like all kinds of things. This is a shower head. This one looks completely different. All of these light bulbs can be screwed into either your existing lighting fixtures or other lighting fixtures that were made to accept retrofit. The other broad category of LEDs are ones that our LED modules made to fit into a purpose-built fixture. And that's what you're seeing on the bottom. And these things kind of look like all kinds of things, like this fixture here with the sidecar. The purpose-built LEDs can also look exactly like your old incandescent retrofit lamp. They can look like all kinds of things. So just to repeat, these two types of lighting fixtures. The retrofit LED, it's a replaceable screw-in LED light bulb or an integral LED, which has a module that's attached. Now, my primary, they can be repaired. Sometimes you can replace the LED with the other associated electronics. It's important to note that it's likely that the associated electronics, whether they're capacitors or whatever, are likely to break before the LED. The LEDs are actually one of the more robust elements in an LED fixture or an LED light bulb, for that matter, or a retrofit. I want to show you some pictures of both of these systems. And I've done renovations of galleries with both methods using new fixtures. This is a retrofit LED system. I did this a few years ago. And in my mind, the integral LEDs weren't quite ready for prime time. And it's a lot that you're looking at. So I'm going to show you this image a few times. But roughly from the left to the right, this is a framing projector that allows you to frame the light. Next heading over to the right is wall washers. And I'll go into how that allows you to provide even light across a wall. Next heading to the right is a spotlight. These can either be floodlights or spotlights, depending on what kind of light bulb you screw into the lighting fixture. This is the smallest flooding fixture of an MR16 with its own little transformer and driver here. And lastly, this has a remote driver. So this is the smallest of spotlights. This is a typical lighting track and lenses that can fit into a retrofit system. What's interesting about these, we have some of these legacy glass, which works perfectly well with LEDs. As long as you ventilate the front of the fixture, when you take these light bulbs and you put them inside of a sealed can, you may find that you are dramatically reducing your lamp life. And you should discount on that. If the manufacturer says 25,000 hours, unless it's an open back fixture, if you're sealing the electronics into a lighting fixture, you may reduce the lamp life. One of the great advantages of LED though is that the front of the beam is cool, so we can use amazing plastic lenses. And a little bit later, I'll show you how we use those. It's also worth noting that the back of the fixture is typically where the heat is generated. So again, if the back is open or ventilated well, you are likely to do a good job keeping your LEDs cool. This is an integral LED system. And my museum started actually installing these quite recently. So again, from the left to the right, this can either be a spotlight or a floodlight. It's not a very good spotlight, maybe a 15 or 20-degree beam. This is quite a great spotlight at four degrees and then two smaller fixtures. Again, with the same capabilities, floodlighting and spotlighting. It's a reasonably simple set of fixtures that four fixtures can really do everything that we need with a whole range of optical accessories. And we'll go into how they're used. And this is an LED framing fixture. So I'm going to talk a little bit more about this integral LED and give you a close-up. So that we've got two different types of lighting sources. At this part of the talk, I'm going to show you the first one, which is the floodlight. So this has got a 19-millimeter source. This particular source actually has six LEDs in it that we can actually create a whole range of different colors with this integral LED. That can be done with a retrofit or integer goal. And there's lots of different optical combinations I'll just show you two here. These two actually bizarrely are the same. And I want to show you how that works. So these are both 20-degree beams, this one in a clear aluminum reflector. And this is lens. And the way that we install these lenses is you just pick them up, you flip them over, and you can see their feed. And we're going to insert them into the optic, like so. That was fast. So that's the aluminum optic. And that's the lens optic. And let me show you what they look like when you shine these things on a wall. Ah, that's great. So let's take a look at these two different beams. This is the aluminum, and this is the lens. Oh, shit. So what's interesting to note here is that the aluminum optic has a, the center of them is a little bit smaller, but the actual, if you measure the intensity with an illuminance meter, they're both equal. They're both about 170-foot candles from my 16-foot ceiling, which is sitting on the wall here. Let me get the cursor. It's a dollar bill. So you can see the scale of how we're working. So the illuminance is about the same at 170-foot candles. We can dim them out. But you see that the aluminum optic throws light everywhere where the lens optic is much more focused. So that's why this particular manufacturer gives us two 20-degree beams. So when you just look at a catalog and it says 20-degree beams, the results can be very different, and I highly recommend that you mock them up. It's interesting if you look in the catalog at the Candela value that the lens optic is considerably less than that aluminum optic, because the Candela value includes all of the light that's coming out of the fixture. Now, if I'm spotlighting something, I definitely want that lens optic. If I'm wall washing, it depends on what I'm doing. If I want to spread light all over the wall, the aluminum optic might be a better choice. Let me show you. Let's say I'm wall washing. This is a typical wall washing fixture where the fixture is open to the wall, but it'll be closed to the public. There's an opportunity to put lenses, reflectors, and this is just a window screen, and it's just great. And this is the simplest way of reducing the quantity of light. Is it the same window screen that you use on your back porch? I suggest that it's aluminum, not plastic, but it works just great. And I'll get back to that when we get to lighting control later. I want to show you how this looks in the gallery. So this is one of my galleries at American Art, and you can see these wall washers are all aimed directly at the wall. And you can see how they're reasonably low glare that you don't see the lighting source so much you just see the sides of the fixtures. Back in the 1990s, we had a completely different system where the lenses were on the front of the unit, and you can see how glaring they are. Both of them are providing even washes of light. Actually, the open lens would spread the light a lot more, but I'm going back to that other image, and you can see that it's much lower glare and a much better look for our gallery. This is a different type of fitting. What I'm showing here is actually how it really doesn't make a difference. You can easily put a retrofit lamp in these lighting fixtures. Now, this tape light can also be used as a wall wash. It's not going to throw the light as high on the wall, but if you put a flood lamp in it and good set of lenses, it'll do a great job. Let me show you. Ah, this is a typical gallery. This is our early modernism gallery, and we've got two layers of light on the wall. One is aimed at spotlights, and the other is just a wall washer. I'm going to turn the spotlights off. Ah, that was quick. And this is a perfectly good way to light a gallery. This is the most common way, which is you just evenly light the wall. Perfectly fine and valid way to light galleries. But what's interesting is getting that even wash is actually extraordinarily difficult. It takes quite a bit of hand skill. What I've done is if you take the lenses out of these units, it'll look like this. And we've all seen galleries that look like this. These are just the scallops of light from a round beam hitting a wall. And some people just try to come up with some type of composition using these scallops that can work perfectly fine. But it really doesn't say anything about the architecture or the artwork of these scallops. It's just what a lot of people end up with because they don't have methods for controlling the distribution of light. If you put the lenses back into the units, you get that even wall wash. Now, these are asymmetric lenses, a 70-degree lenses that are spreading the light horizontally left to right. This is the power of asymmetric lenses. Let's turn the spotlighting back on to that other layer of light. And I'm going to turn the wall washing off, and now we just have spotlights. Now, what I've done here is I've tried to take the spotlight and match it as exactly as I can to the size of the artwork. So a small artwork gets a small beam of light, a large artwork gets a large beam of light. And on top of that layer, I add my wall washing back in. Spotlights allow me to take these darker artworks, these low-reflectance artworks, and have them be brighter as compared to the white wall. I wouldn't do this with contemporary art, but for this early 20th-century art, and especially 19th-century art and earlier, this technique of spotlighting can really be powerful. It depends on the aesthetics that your museum is after, and also the degree of skill of your staff. If you don't have people that are really trained in order to do this and as much as being trained have the time and patience to do it, then the simpler methods are really best. Distribution is so important. I'm going to keep on talking about it and show you some examples of spotlighting. So this is a great Western quilt show that we did again at the Renwick a few years ago. What you're seeing here is work light at about 50 left. And I'm going to show you the power of spotlighting. I brought my team in. We spent about 40 hours with two of us, adding a bunch of fixtures and very carefully aiming the lights. And this is what you end up with. This is the power of focused light. When I'm designing an LED system or any system, and that's what we're doing here today is you're likely going to be considering buying new lighting products and why you're doing it by the most flexible system you can. This is the range of beam spreads that I purchased from my lighting system. These are the kinds of choices you're making about what kinds of beam spreads are important for your museum. If you're in an art museum, I really do recommend the 4°. I find it quite powerful. And I actually use that often as an engine to create lots of other beam spreads. And my latest designs only basically are built from a spotlight point of view from a 4°. And I use that as an engine. And with lenses, I create the 8° and the 15°. And then I've got a floodlight, which is within a 25° and 40° beam. Again, the secret of lighting design I'm told is to put the light where you want it and take it away where you don't want it. And this is the power of narrow beam lamps. So that 4° beam has the capacity to this. Put the light on the pedestal and get that ugly light off the floor and where you don't want it. And also that extra light becomes glare in the viewer's eyes. Again, this is the power of a 4° lamp. If you're a cultural museum, a history museum, a natural history museum, this 4° beam certainly has its uses. This experience is that often larger beams of light work quite well for those other types of museums. It all depends on what you're trying to do and to use the best lighting technique you can. So I wanted to show you what the 4° looks like in the retrofit system. It's this 3-headed unit. And I helped develop this particular light bulb for a renovation of the Renwick a few years ago when we were going all LED. There's also a 15° spot and a 25° spot and a 40° spot. On the retrofit side, I'm sorry, on the integral side, again, blood light. And starting with that 19mm, there's a 40° flood, 20° spot and a 70°. Actually, my bad, it's called a 70°. It's actually, I think, a 40° flood. This is a 4° spotlight. And then we take a whole range of different lenses, add them to that 4° to come up with a whole myriad of options. Let me show you. That's a close-up of that 4° integral spotlight. It's got three different LEDs. Where the flood is a 19mm, these are little tiny LEDs. I don't know how big they are. They're only 2mm, so you need a tiny little store size to create these spotlights. As soon as you add lenses to start making the light a little bit bigger, you really want to add a cross-baffle to keep the light from being glaring with the viewer's eyes to create that rectangle. Let me show you what it looks like. On the left is that same light that I showed you before, the 20° lens optic at a 19mm. This is not the smallest spot as you're going to get out of a 19mm source. This source is just so huge you would need a reflective size of a garbage can to get it in the tighter. You can get a little bit tighter at 15°, but not much. That 4°, you can see how small it is. That's a 4° spot, and you can see that it's just a beam. The area outside of the beam is called the field, and there's not a lot of field here. You can see that it's about the size of maybe three or four $1 bills. Oh, at 16°. That's what the lighting fixture looks like. You can do this in retrofit. That three-headed light bulb I showed you looks about the same on the wall. You can achieve the same quality, whether you're going retrofit or integral. You're just going to be spending a little bit money on the integral, and I have a feeling that it will last you longer. This is an example of how those plastic lenses can be used with a 4° to spread the light in all kinds of combinations. I'll show you in practice how we use that to light a gallery. This is from the Renwick Gallery's inaugural exhibit, when we reopened after a long renovation. This is an artwork by Maya Lin. What you're seeing here are small modules of light. These are the raw material that Maya Lin's father used to blow glass with. She took these small glass marbles, and she created the watersheds around Washington D.C. On the floor and on the wall. This is the Delaware Bay. This is the Chesapeake Bay. This is the Potomac River, with Washington D.C. being right here. What I love about this is if you were to look out this window, about a half a mile down the street is the Tidal Basin and the Potomac. I just love that this part of Maya Lin's artwork is giving you a real sense of place. Now, I lit this. We all thought it should be lit slightly. The exhibit is under the curator because it's a contemporary artist. We're featuring the building. After our first preview, Maya Lin came to me and said, what have you done to my artwork? I'm like, what are you talking about? She said, I hate flat lighting. I want Kira Skiro, and I want something completely different. I got to spend the day working with Maya Lin, and this is what we came up with. We took that technique that I just showed you of a four-degree lamp along with these holographic lenses, and we created rivers of light on top of her rivers of glass. It was super successful and a real honor to be part of Maya Lin. We recently, just a few weeks ago, finished the gallery you're looking at with integral LEDs. The previous slide I showed you from Maya Lin was retrofit. This is integral. These blood lights have the capacity to change color. We can choose a whole range of colors. We actually didn't spend too much time on that. I'm going to spend some time talking about color in a moment. While we're talking about distribution, that turned out to be the most important. When I got feedback from my curator, that's what she cared about. She cared about the quantity of light, that she wanted as much light as possible right up to the conservation limit, and she cared about the distribution. If I'm spotlighting these at all, she's uncomfortable with me spotlighting these works of contemporary art. She wants to see no halos around the artwork. It should be perfectly blended, and this ability to decide how tight a beam of light or how soft a beam of light are all aspects of distribution, and they were absolutely the most important thing when lighting this gallery of contemporary art. With that, we're going to have a discussion of spectrum, and that when you're choosing your lighting sources, how do you choose aspects of spectrum? At this point, I'm going to talk a little bit more about LED technology, and how LEDs create white light, little on-color light. First, we're going to talk about phosphor converted. I know that's a fancy word, but it'll come a little clear as after I show you how. There's actually three types of phosphor converted lights. Blue LEDs, violet LEDs, and ultraviolet LEDs, and all of these are short wavelength energy. On their own, they can be actually destructive to artwork, especially ultraviolet, which is why we don't use ultraviolet LEDs. There's not a lot of them on the marketplace, and you really want to make sure that you're not using ultraviolet LEDs. At this point, I wouldn't even know where to find a phosphor converted ultraviolet LED. It just aren't very common on the marketplace. Violet LEDs aren't very common as well. There's one manufacturer that markets to museums. They're actually really good light bulbs, so honestly, I sometimes use them. They're a little bit more damaging than the blue LEDs. The blue LEDs might be, say, 20%, 10% more damaging when less damaging rather than some materials than incandescent. Let me repeat that. Blue LED converted LEDs are a little bit less damaging than our legacy incandescent and halogen, where violet LEDs are roughly equal to what we're using now if you're using LED incandescent. It's basically a wash. If you have a choice and everything is equal, I prefer blue LEDs, but if you have to use the violet LEDs, they'll probably be fine. It'll take me about a half an hour of really technical explanation to really discuss why violet LEDs are likely good. Let me show you how all of this works in the phosphor converted world. We start with phosphor. Phosphor is a powder, as you see on the left, and one of the manufacturers took this powder and they actually applied it to a piece of silicone, which you see on your right. What I did was I smashed the light bulb and I saw that the light bulb had blue LEDs and this phosphor disc. And here you see me in blue being lit by the blue LEDs. The most white LEDs you see out there are actually blue LEDs. And you can see how the phosphor disc is glowing unnaturally. As I get that disc closer to the lighting source, it gets even brighter. And when I completely occlude the blue LEDs, it turns into white light and really high quality white. So this is the spectral power distribution of a typical blue pump phosphor LED. One, the y-axis is absolute irradiance and microwatts per centimeter squared per nanometer. And one, the x-axis is wavelength in nanometers. And we can tell it's a blue pump phosphor light because there is the blue pump, there's the LED in blue, and here's the phosphor. And this is what happens is after you expose the phosphor to this short wavelength energy, it actually down converts into something that appears white. And it works great. Blue and yellow make white light. Some people are very concerned about this dip. I highly encourage you not to be. This graph will tell you very, very little about this particular LED's qualities. It doesn't tell you that much about its color or its ability to render colors of the artworks we have in our gallery. Like I say, this is a graph of energy, not of quality of visible light. What this graph does tell us is about energy. So if you're interested in energy, let's say UV energy, it tells us that there's no UV in this light bulb because we're starting with blue. Violet LEDs also have virtually no ultraviolet, the most destructive light that doesn't help us see. Well, on the other side of the spectrum is infrared. Also a great thing about LEDs, whether they're violet or blue, is that we're getting the heat out of the gallery. This is a huge benefit. My mechanical engineer, when I'm using incandescent, I'm at 5 watts per square foot. That's a massive heat load. It takes them many hours to regain control over temperature, humidity, and dew point of my gallery because there's so much heat being generated by my incandescent. We're trying to create stable environments for our collections and incandescent lights are not helping, they are hurting. We also have to cool that incandescent load, and there's additional energy savings by getting this IR energy out of the loop. In the middle is what we call light. And that's one of the great things about LEDs, that we're starting with visible light, create light, rather than the other lighting technologies where we're either creating a massive amount of IR, 80% of incandescent's energy becomes heat, not light. Remember my test bed of all those LEDs? Every single one of these LEDs that you're seeing are a phosphor-converted process, which takes us to multicolor LEDs. Because we all know that red, blue, and green can mix to white. And I want to really thank Wikipedia and the person who made this image, BB3CXV for creating these images. And I can't thank Wikipedia enough. There's so much of the sharing community where we can go out and get these images and get actually often really good information. I don't rely on them for my vision science information. Thankfully, I've got vision science, the color science that reaffirms materials. But I'll tell you, if you go to Wikipedia and you look up CIE and the CIE charts and a lot of the vision science data, it's very good. I don't know who's writing it, but it's really extraordinary. I'm really grateful to Wikipedia for these images and for all that great information out there. Multicolor LEDs, red, blue, and green, mix to white. The quality of light, if you're just using a red, blue, and green LED, honestly, may not be very good. Often offering, adding rather a fourth LED really improves the quality. There's lots of systems where you get red, blue, green, white. Works much better. I specified one last week, and it was quite successful. That system actually allowed me to determine which color white LED I wanted. Red, blue, green, amber. That used to be more popular. The latest systems are actually red, blue, green, lime. I know several systems that are really extraordinary using those color combinations. The lime being the closest to our human vision and kind of evening out the whole spectrum and increasing color rendering qualities. There's any number of combinations of these. My favorite lighting system uses red, blue, green, lime, deep blue, amber, and cyan. I do great work. We've got a David Hockney painting where we're lighting it with that type of system. This system is so good that the folks at Pacific Northwest National Labs in Portland, their vision science lab is actually using that same engine. You can do these multicolor LEDs in either an integral or a retrofit. There is a retrofit LED out there. In the base of this LED is a radio. That's how we are able to control the different colors. Once you get to multicolors, you need advanced controls to utilize them. This LED can create all kinds of spectrum. This is a high color rendering. We're going to talk about color rendering in a moment. Spectrum or a spectrum that looks like this. This light bulb can create red, blue, green, all kinds of colors, millions of colors probably, as well as at any one color, give you different color rendering possibilities. It's extraordinary, and that's the last next part of our talk. Because when you're choosing an LED, you're always making two choices, even though both of these are labeled number one. The two choices that we're making, and they're equally important, I suppose, are chromaticity, which is the color of light, or the color rendering qualities of that particular color. Let's talk about this. Welcome to my shop. I've got a lot of light bulbs to test, and you see on the back wall there are two color checker cards. If we take a close look at them, what we're assessing are these two qualities. Color rendering, which is a light's ability to render a broad range of colors, or chromaticity, which is a big word for the color of light, as it appears on the white surfaces. That's chromaticity. The way that we measure color chromaticity is on one of these fancy kidney bean charts. This one was developed in 1931, as they're developing a lumen, and this one shows our visual field. So it shows that we see mostly green with some red, some blue, but our visual system is really sensitive to green. You see this curve. This curve is called a locus, and the color temperature locus, or the Kelvin scale, describes the light from warm and red to cool. Counterintuitively, the warm colors are lower numbers. So typical warm colors are 2,700 Kelvin, which is what you're going to do to match incandescent. 3,000 Kelvin more closely matches halogen, and you get cooler and cooler. Daylight is between, I don't know, 4,000 and 10,000. 3,500 to 4,000 is often considered neutral. This is the Kelvin scale that describes from red to blue. There's another scale you may not have heard of called DUV. It's actually measured on a slightly different CIE chart, but we can describe it here. That's measuring pink to blue along the isotherm. The isotherms are the lines that are in the DUV chart, perpendicular to the locus, and it describes if it's a negative DUV, it's going to be below the locus, so it's going to be a pink light, and if it's a positive DUV, it's going to be a green light. So a lot of people have heard about this Kelvin temperature, color temperature, very useful, but human beings are actually more sensitive to pink to green shifts, and now we have a metric to measure it. Another useful part of this chart is if we were to plot three points, say a red light, a green light, and a blue light, and draw a triangle connecting them, that shows you the potential different colors you can mix with three colors of LED. Very useful chart. We're often asked, what is the right color of light for being our one? And in my opinion, there is no right color. This is a matter of taste. People will argue fiercely about this, that they know that there's a right color. I've seen museums all over the world drive themselves crazy trying to find out what the right color of light is, and I don't believe there is one because of what my color scientists tell me, that if we're put in any one environment, we will white balance to any color of white light in about 30 seconds and fully adapt in two minutes. So for example, my contemporary art gallery, and I'll give you an answer, if you have to choose one color in 2019 to light your galleries, I recommend 3000K. Perfectly good, but it really depends on what your environment is and what you're trying to do. You can see that the 3000K looks reasonably white. It may look a little bit different, perhaps a little warmer than the outside light, because we see light as an interaction of color, between in this case, the daylight here and the light on the galleries. And the 3000K is also a good mix. The next gallery over is still incandescent. It's a type of incandescent that actually looks a little bit green. So you're going to see the color of light as it differs from the adjacent gallery. Or if you want to use this powerful property of movement, you can have one calorie be a little bit warmer, a little bit cooler, and then you're going to start seeing the interaction of color. But the difference between 2700 and 3000K may be apparent, but don't drive yourself nuts. Yes, there's a difference, but it's not as large as you might think it is. How do I know this? It's because I work in an art museum, and we have Joseph Albers on our side. And us within art museums should know Joseph Albers, the great teacher and artist of the 20th century, taught us. He claims to see colors independent of their illusionary changes, goals only himself and no one else. And a few years ago, the Albers Foundation at Yale published an iPad version of the classic book, Interactions of Color. So instead of having to cut out color aid cards that many of us use at a do for our design classes, you can now do these experiments very, very quickly when an iPad. So this is one of his experiments. So these two colors, as you may have guessed, are the same. The center of this square and the center of this square. Let me show you. This is the power of the interaction of color. And when you're choosing for the colors of white light for your galleries, it's exactly the same idea. Let me show you another example. This is a very fancy LED wall where the LEDs are behind the curtain right here. And we can change the color of the wall. So I'm going to show you how the color of the artworks themselves do not change. But by changing the background, we'll change the apparent color on the artwork. And here we go. Ah, there. Did you see how yellow that went? Let me show you again. So by changing the color of the back wall, the color of the artwork actually changed. This is the power of the interaction of light and the interaction of color. A few other tips about chromaticity. If you're buying this instead of light bulbs, it's nice to aim a bunch of them at the wall to see that they're all the same color. It's also useful if you take, after you see that they're all the same color, to take one, put them in the closet. So over time you can see that they haven't changed. I'm going to take these light bulbs, drop them down onto the canvas as a unit of light. That's how I lit that painting. And this is, again, a color stability over the time. I was testing in 2011. My light bulbs absolutely were changing color. And I used my fancy spectrometers to measure that just after six months, I got six noticeable differences of light, which is quite extreme. It kept on changing color. The new LEDs today absolutely are more stable, but LEDs certainly can change color over time. We're not going to talk about color rendering. I'm going to try to pick up the pace a little bit. So there's two aspects of color rendering. There's color fidelity. Does the color of a particular spectrum match the reference color? And if it doesn't match, does it make things more colorful or less colorful? I'm going to introduce a fancy word called metamerism, which many of you are familiar with from in painting. Metamerism says that you can have different spectrums of light, and they can all appear the same color. So each one of these different colors of light represented in these energy graphs are very close in color. And these are all LEDs, again, different shaped spectra, but they will all appear the same 3,000 degrees Kelvin white. That's the power of metamerism. There's something called a metameric calculator called the color rendering index. This one was developed in the 1960s. They use these eight STL colors, and all that is doing is saying we've got a reference light, which is exactly the same color as your test light. So if you're testing a 3,000K LED, your reference is 3,000K, basically incandescent, it's a black body theoretical light. And with this thing, is there any difference between the test and the reference? We average them all together, and we get color rendering index. There's a better way. This is recently developed by TM30, scientists named these things, and the pneumatric uses 99 color samples. This is about to be adopted by the international community, and it's really a much, much more robust way of measuring how a particular spectrum of light will allow us to see a broad range of colors. This is called color rendering. Let me show you an example from my lab. So we've got, I'm just vainly doing the same thing that the metric should be doing. I've got a test light and a reference light. Let me try that again, a reference light and a test light. And you can see that these two are roughly the same color on the wall, maybe a little bit different, but pretty close. But the way they render the color checker is very different, with the red here being a little bit more dull than the one on the right. Let me show you how I measured these lights. First of all, the spectrum, that the spectrum up here is a little bit smooth. When you see a more spiky discontinuous spectrum, that's possibly going to make things look more colorful, which is counterintuitive. It's really hard to know how these energy graphs will affect color appearance, but that's how this one is working. If you take a look at what color of light on the left and the right, they're basically the same color, very, very similar. And the metrics show fidelity. The one on the left is very close to an incandescent reference source. The one on the right is actually much lower with a color rendering index of 46, despite its ability to make things look more colorful, especially red and green things, as you saw on the color checker. So this might be a little bit more confusing, but what it's saying is that our old color rendering metrics, DRI, may not tell us that, yes, there's a difference between the new light and the old and the reference light, but the difference is that the new light is making things look more colorful. And these new metrics, TM30, give us an idea, especially with this color vector chart up here, how it's changing between the test and the reference. If you want more information about TM30, here's a link and that's included now in the handout that Susan got together for us. This was put together by Kevin Hauser, who recently joined the team at Pacific Northwest National Labs. For now, it's still being hosted at Penn State University, and he just started a new job as a professor at Oregon State. Thank you, Kevin Hauser. Movement of light. We're not going to be talking about angle today because that really is about where you put the light, not what the light is. We're going to limit our discussion as we wrap up today just about the qualities of choosing an LED itself and for movement, the most important part is flicker. That poorly constructed LEDs will flicker. It's hard to assess flicker. Some people just see it and they know that a source is flickering. I'm asking about 10% of the population is flicker sensitive. I need one of these fancy wheels that I happen to get back in the fluorescent days when we're switching from this fat tube that used to flicker to the thinner tubes that do not flicker. If you see a hex pattern on your flicker checker, that indicates flicker. Flicker is bad because it can cause headaches for some people. It's another trigger in the environment for people with autism, and it could be for photosensitive epileptics. I do not specify lamps that flicker. Retrofits are more likely to flicker than intracool LEDs. You have to test whatever you're using. If you add a dimmer to the system, it's more likely to flicker. I took a look at one of our galleries and I added a light that flickers. I could show you a method for testing if you don't happen to have one of these fancy wheels. What you do is you take your camera and you have a slow motion video feature. That slows down the flicker rate by a factor of five. This may or may not work, but it certainly worked today when I tested it. Mike, if you can take it away and start the video, we'll show you what a slow-mo video of flicker looks like. There we go. You can see that light pulsing under slow motion. I filmed for about five seconds and mine, yeah, there it goes. It's showing up a little bit better. This may or may not work. For, I don't know, it's hundreds of dollars. It's not close to a thousand dollars. You can actually buy an accurate meter to measure flicker. I haven't found the funds to buy one yet, even though I certainly am looking to purchase one so I can do a better job assessing this very important feature or deficit of some types of poorly constructed LEDs and the old fluorescence, which we hated so much. I just wanted to thank Naomi Miller, my mentor, and guru, one flicker. Naomi also put this into one of her talks where this is a sample specification language that you can write into your specifications if you want to demand a relatively benign flicker level for your archaeology. Flicker can exist. The idea is that it exists above human tolerances, and I'll give you a moment to take a snapshot of this. It's based on IEEE 2015, which I believe is still the only standard for Flicker. The standards community is catching up trying to assess this very important component of light. Next up is occupancy sensors. The only contestants would burn out if you turned them on or turned them off. LEDs are happy being turned on and off all day long, which makes them especially good to use occupancy sensors for and just works great. It gets complicated to associate them, but I highly encourage it because if your artwork is being lit by the most light-sensitive materials or being lit, they're being damaged. Quick review of lighting controls, and we'll wrap up. I talked about with window screens and color filters. You can just put these inside of your lighting fixtures. They may heat up your lighting fixtures, so be careful. But I often will put one, half of a window screen. Up to 10, 15, there's no limit to the amount of window screen, but it may heat up your LEDs reducing the lamp life. It's a mechanical system. It works great. It doesn't change the life on the color of the light, and it lasts forever. Dimmers certainly work great. They may be centrally located. If you've got a centrally located system, you have to match your retrofit LED or your introfit LED with these central dimmers. That can be complicated. You may want to involve a professional to do that. One way to do it is you want to make sure that the only load on the system is the LED itself. As soon as you add what they call a resistive load, like an incandescent light, it cleans up the system, which means actually that it's not an energy wasting, but if you're having trouble with light flickering or whatever with a dimmer, adding an incandescent lamp into the system may clean up some of the problems. One board fixtures. More and more companies are actually giving you a little dimmer when the fixture themselves. That works great. But if you want to use any of the fancy color changing LEDs with the radio inside, it may not work if you're using any of these centrally powered dimmers. These dimmers, when you're dimming the actual voltage to the LEDs, are not the best way to do it. It's like taking your computer and putting a dimmer on your computer because LEDs are in fact computers and expecting your computer to work perfectly well with a reduced voltage. LEDs can do it. Sometimes they work well, but the results vary and you really have to match your LED to your dimmer. There are a number of companies out there that will help you match your LED to your dimmer and you can reach out to them for some system. The last way and the most complicated way is computer control of every lighting fixture. You can now do dimming and or color. You can do it wirelessly with a retrofit with something like ZigBee as a wireless protocol or Bluetooth low energy. There's also data track which has a separate run of wires inside the lighting track which you can do sophisticated computer controls. At this point you really should be working with a lighting designer to really figure out the details. You can also potentially run a wire through every lighting fixture. That's a short run down of lighting controls. It gets really complicated really fast. With that I am prepared to take questions and that's the formal presentation. I'm now opening up my screen so I can figure out how to actually take questions. Okay, I'll read them for you. How's that? That would be fabulous Susan, thank you. Okay, our first question is what's the name of the glass artist that you talked about in the beginning? Oh my God, Lino Tegliopatra. I'm a huge fan. I love that question. And just for the record, this talk will be stored on the website, correct Susan? Yes. Because I know I presented a massive amount of information today and by having it be available you can go back, take another look and please whoever is doing the lighting in your museum whether it's a preparator, a curator, a conservator, often it's the mechanic in the galleries, share it with them and allow them to see it because I think the people that are actually doing the lighting can get the most use out of this material. Rosanna, I'll get the spelling and I'll put it in the handout and I'll add it. And it's also in the PowerPoint itself. Okay, Michelle Egan Eagle says some light fixtures just won't work with LED and they require an incandescent to stay on. Is that true? I'm sorry, I didn't understand. Could you start? The question again, I didn't quite get it. She says some light fixtures won't work with LED. They require an incandescent to stay on. Is there a solution to that or do you have to get a new fixture? Sure, so this is something I'm excited to go into. When I talked about retrofit, I only talked about ruin light bulbs. There's another class of fixture called R36 or AR111 or even an MR16. All of these fixtures have transformers in them and you can retrofit them. It's more difficult, results may vary, but there are retrofit lamps available for them and they often work pretty well. Besides that, and I'm glad to cover that very important component of retrofit lamps because it's really a widespread problem. It's easier to do with it if you have a screw and light bulb, but that's about the best I can do to answer that question. Okay. Rosanna Kwan-Bess, is there any way to find out the decoloration rates from LED sources in hours or years? Sure. Within Illuminating Engineering Society, IAS, there's a few standardized reports and the good lighting manufacturers will provide these reports. The most common is called LM for lighting measurement. I forgot what it's called. LM79. I used to know. I probably have a report around here somewhere. So LM79 will give you some ideas about the rate of degradation of your LEDs. There's also an LM80 report which is more at the LED point. My favorite way is actually what I said in the talk which is take a light bulb that you know is the same color as the rest of them, put it on the shelf, and then you can test. If you have a spectrometer which they're getting more and more affordable, you can get kind of accurate one for about $1,500 and a quite accurate one for about $5,000. Then you can measure the color of LED right at the source and then you can see how it's changing over time. So those are a couple of methods. You can get a spectrometer app inexpensively for a cell phone. Yeah, I tried them. It's not going to be accurate. Yeah, right. So any method of measuring color from an iPhone or a smartphone is not going to be particularly accurate. If you want to do reflected color of a paint sample, there are a few small little disc products out there that cost about $50 that you can associate with your iPhone or smartphone, Android, whatever. And those little discs have an integral LED in them, so they've got a reference lighting source. And that will measure a paint sample, but if you want to measure the color of light, you need some type of spectrometer in order to do that well or colorimeter. Okay, Jennifer John says, what are your recommendations for a house museum? It's hard to incorporate LEDs into these old houses, and I am going to also bring over the evaluation link. So I'm going to put it up here and please fill it out. We really use the evaluation. So if you can talk about historic houses. Oh, I'm sure. And as I started off, if you have a solution for incandescent light, they are really cross-applicable to incandescent light. And what this great moment of switching to LEDs does, it allows us to revisit the power of lighting design itself. So getting electric, the electric lighting is the hard part, and LED in some ways is a lot easier because you can do low voltage. You've got a whole range of possibilities that you didn't necessarily have with incandescent. So I mean, that's a sideways answer to the question. Historic homes are really difficult, and whether you're deciding to put a sconce on the floor or an uplight a ceiling and do it that way, which is a common way of lighting historic houses, or trying to get these, the LED retrofits are getting better and better if you already have electric lighting in there. Historic homes is all application dependent. It depends on what kind of access do you have to the plenum in your ceiling to the floor to getting power in there at all. And power is often the biggest challenge as much as the lighting is. Okay. And Chelsea Kagan had basically the same question. Stu Lauderbach says, what's the best source for LEDs? Can I go to the hardware store, or do I have to buy them through a museum lighting source? Oh, so this is a great question. Yes. And I actually had meant to reach out to the distributors, do a little bit more research on this before we talked. You don't have to go to a museum supply for one thing, but the two competing places are your big box hardware store versus your electrical distributor. And your electric distributor in your area often has somebody who specializes in lighting. It's often the smartest person in your community for lighting. So I highly recommend that you go to your local electrical distributor. They're in our communities, and it's a great resource right there in your hometown. The big box retail are unlikely to have anybody that really knows what they're doing with lighting, but the samples are great. And the quality of LEDs that we're getting at our big box retail are often very high. They don't necessarily have all the choices. Your electrical distributor will have many, many times more choices than you'll find at your big box retail supplier. But I often do buy samples at the big box. They're often as affordable. I would encourage your electrical distributor to match the price of your big box retail. They may not be able to. And if your local electrical distributor charges you a little bit more, but they're worthwhile your time because they provide such good service. You're going to get better warranties and warranty service out of your electrical distributor than you will out of your big box retail. So I just thank you very much for asking that question. I really did want to get to that and provide that information because it's so important. And Holly Chase asks, we have long fluorescent tube lights in our galleries for porcelain. Is there a type of LED retrofit for fluorescent ballast? Sure. I actually know relatively little about this. I've been looking at the market for a long time. I have not done any of this retrofit myself. Remember when we talked about flicker? A lot of, especially the inexpensive LED retrofit that you'll find online, a lot of them flicker terribly. Also, a lot of them are super glary. If you see an LED tube, we see the little dots of LEDs, whatever kind of LED. They're often terribly glary and not worthwhile. There are some LEDs that are quite good in this fluorescent class. I've been seeing them at the trade shows getting better and better every year. But one of the downsides of fluorescent LEDs is that they don't provide lighting 360 degrees around the tube. They have a tendency to be directional and only point light in a certain direction. For your porcelain case, that's probably fine. But it depends on how your fluorescent is working. It could take, like, say, an office and turn it into a cave with all the light aiming down and none of the light aiming up, which is often what we want to do with the fluorescent tube. I still use fluorescence in certain applications. I did an exhibit by Doho Star last year where I specified fluorescent tubes because fluorescence have a unique ability to spread light 360 degrees, and that's really hard to do with LED. Okay. Anne Schäftel says, I work in monasteries in remote areas of the Himalayas where any LEDs available in the market are of unknown quality from India or China. Can you warn us of dangers from unstable or poor quality LEDs? Since we are recommending that monasteries remove old tube lights and use the LEDs available in the local market. It is such an honor to be here and to speak to this global audience. Wow. My understanding is there's little risk that because, for a couple reasons, one is LEDs are lower wattage than the legacy incandescent. The lower the wattage, in some ways, the lower the risk, the lower the heat. Also, what's most likely to happen is that the electronics are most likely to fail. It's less likely that they may catch on fire. So that's my understanding is that it's a reasonably low risk of adding these electronics into your spaces. As far as the quality, that's a different story. Certainly, within the United States, we're looking for nationally tested, recognized laboratory symbols in our works, whether they're from the EU, and it's the CE, or whether it's UL in the US. But there's a whole list of labels that will tell you, has this device been tested? And I don't know what they are in the countries that you're talking about, but I'm sure they're electrical testing laboratories. And that's our recommendation to make sure that it's at least not going to burn the place down. Okay. William Bushmeyer says, we have all fluorescent lighting, so it's best to determine the number of tracks to go all LED for a specific room. So I think what he's saying is, how do you determine... Well, William, can you clarify what you mean, please? He says, we have all fluorescent lighting, so how best to determine the number of tracks to go to an all LED for a specific room? So he posted that twice, and he's writing something up now. So mockups are great. I see a lot of technical information out there, which people may find useful. Mockups are wonderful. And absolutely, whether you use the technical information or not, mockups are the gold standard, and if it looks good in the room, it is good. So get your hands on a few light bulbs and start working with them. And you can see how one light bulb works. How three light bulbs may work in combination to form a single system. And then you can extrapolate from there, see how many lights you need to light your entire room. If you're thinking of even illumination, even illumination is often boring. And we often want some curious keros, some light and dark, to create a really dynamic fire. Okay, he adds, how to design the tracks needed for a particular room for an electrician? So I guess if you're doing a conversion, what do you tell the electrician? Well, I can't provide any advice for electricians. You need an electric engineer. But for galleries, you have enough lighting track in your space to put the light where you need it. It depends on some ways, what kind of gallery you're talking about. If it's a paintings gallery, you want basically a 30 degree angle off the painting to the first lighting track. I often like having a 45 degree angle from the painting to the next lighting track. So I've got a variety of angles. In my galleries of like 15 feet, I often put lighting tracks every four feet. I put a lot of lighting track on my ceiling, so I have a lot of options. And doing that when you're at the renovation stage or at the new construction stage when it's the easiest. The higher the ceiling, the farther apart lighting tracks can be, the shorter the ceiling. The closer lighting tracks need to be because the light doesn't have as much space to spread out. If I'm working with a lot of objects, and if there's a lot of objects in these types of galleries, whether it's craft or whatever, I often put a lighting track very close to the wall so I can aim straight down into a pedestal. And as far as how to wire them for an electrician, I'm going to depend on electrical engineer on electrician to talk to you about the electrical capacity. The one thing that I can say is that, and I alluded to this in the talk, the incandescent loads, we were figuring five watts per square foot. The LED systems I'm installing now are closer to one watt per square foot or even less. So our electrical demand is significantly less and we can feed our tracks less often. So William says that was very good information. Thank you. Holly Chase says, so I didn't quite catch all of this. Are you saying that it's problematic to just buy a LED MR-16 compatible light for a regular MR-16 fixture? No. Actually, I didn't talk very much about MR-16s. I can't now. Thanks for the question. No, these retrofit lamps work great. And if they work fabulous, if they work with your dimmer, that's just great. Whether they continue working with your dimmer over time, that may vary. But you just deal with it as it comes. Do whatever you need to get your museum up and running, to get your conversion going, and there are no rules except to kind of make it work. On the MR-16 side, because it's such a small package, I found it the most difficult lamp to retrofit. But there are a few companies out there that I use. I use the MR-16 retrofits. I've had very good success with some of them. I've also had more failures than any other type of lighting source as well. So absolutely I would use the MR-16 retrofits. And if they become too frustrating, try a different manufacturer. If that manufacturer fails, try a different manufacturer. Stick with a single manufacturer and make them make good. Maybe they can work with you and tell you why you're having troubles. A lot of these LED manufacturers are wonderful. I find a lot of them to be really honest and reputable, and they really want to help you and help you solve your problems. So help make them a partner in your process. Okay. Holly has another question, but I want to get to Jeanette Halverson's question. Is there a specific lens to use to cut down on glare from high-gloss artwork? Sure. No. The answer is no, there isn't. So I can keep on going. My only idea that I've ever had about this is that I could polarize the light and then make everybody and all my visitors wear polarized glasses. That was a really geeky joke. No, so that's really... But that last property of light that I didn't talk about today is angle. And I believe in the other webinar that's online, I go into how we reduce reflected glare off of artwork by manipulating the angle of light that hits the artwork. And that reflected glare is really all about angle. Okay. And Holly says, do you have MR16 LED manufacturers that you recommend? There's some that I've had better success with, and I'm honestly a little bit uncomfortable listing manufacturers. I mean, part of it is... Yeah, I'd rather not if that's okay. And I'm sorry about that. I know that it's probably valuable information that's important to the users, so I'm a little conflicted about where to go from here. No, I think it's fine. We're not in the business of making recommendations for things. So Anne Schaftel adds, the monks were afraid that the LEDs might explode when the current fluctuates as it spikes and dips often. I've not had... Is there a form that people share information? I mean, I'm on the packing list serve. I'm on the list serve for this organization. Yeah, Anne, you might check in the AIC regular list, not the Connecting to Collections community, because this is more of a conservation question. Sure, so... Right, so for both of these questions, I have not had any problems with LEDs exploding or causing fires or anything like that. I have had problems with my incandescent fixtures doing that in any number of times. But so far, not with my LEDs. But put it out there to one of these list serves, as well as your manufacturer's question. These list serves may be a really good place to get some information about that and to reach out to the community and talk among ourselves. Okay, so I will post the recording, the handouts, and the PowerPoint slides in the next few days. And Rosanna, Kwan, I'm not really sure what you're asking. I will check the links in the handout to make sure that they work. They were working this morning, and I think that's what you're asking me. And in the meantime, thank you so much, Scott. Thank you, Mike, and welcome, Robin. Bye. Fantastic.