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One of the first1 moving-head LED lights that I saw was the GLP Impression X90. Having spent the – well, not years exactly, but enough time in the biz to figure out that the MAC 2000 was more or less How We Did Things, it was pretty nifty. It was small, it was – in deep colors – punchier than moving heads three times its size, and it was blazingly fast in moves. It was a very cool light; a step in the ladder of advancement that had been in motion since we stopped burning bits of rock.

The Impression – and back then, we all just called it The Impression, because there weren’t others – made a real splash. Rarely had I seen a red that red out of a fixture2. Such a sheen inevitably wears off after a while, of course, especially once you really dig into the colors. A certain sort of white came out of that front array of Skittles-like RGB emitters – a magenta-tinged mess that, if you twiddled the knobs hard enough, you could sort of browbeat into an approximation of an arc source. Dialing up anything south of 5,600K, though, and you were greeted with too red, or too green, but never quite the pale amber that you were going for. Trying to light a human with this would summon abbysal hair and skin tones from the depths, and no Lee filter or gel picker would help you now, mortal. The entire yellow range, in particular, was a weak point from the very beginning of RGB.

Of course, this is a practical consequence of using very narrow-bandwidth emitters to approximate a full spectrum of light. “Approximate” isn’t even the correct word, because it implies a sort of emulation. That isn’t what RGB is doing, really. Sure, it’s stimulating the cone cells and producing constituent parts of the photopic experience of yellow or white or whatever, but there are broad contours that get lost when you’re using the spikiest spikes and discarding the gentle slopes of the rest of the colors. You lose what is essentially a very pleasing sort of reduced contrast.

Then along came the Vari-Lite VLX3, audaciously upping our color count to four. You probably all know this by now, but every white LED you’ve ever seen began its life as a blue LED with a phosphor coating over the top to convert most of that blue light into a white spectrum. This helped immensely with the pastel parts of the color range, and we could finally point LED-based lights at humans without completely regretting it. But this is an imperfect solution tacked onto an already imperfect solution. The white isn’t a magical Fill-In-The-Gaps color that prevents metameric failure, it’s a blunt across-the-board tool. Because of the blue pump, early attempts produced a spectrum dominated by a blue spike, and even with today’s advancements we still have almost non-existent reds and ambers. White really does nothing to address the gaps in the spectrum, it just smooths them over for when you’re trying to make pastels.

What Lime – and to a similar extent, Osram’s Mint – did was to change some of that for the better, along with amber. “Direct amber” LEDs have been around for a while, but in 2009 Philips Lumileds created a phosphor-converted amber LED with a 30-40% efficiency. Adding to that, Lime and Mint fall right into a highly-sensitive part of your eye’s photopic curve, so a properly-tuned array of this quintet of LEDs (red, green, blue, amber, and Lime / Mint) produce some of the best color mixes we have available to play pretend-tungsten in this post-tungsten world. Emulating this should-be-dead source, however, isn’t the only thing we want to do, though it does suck up a lot of the color-mixing air in the room. Theatrical productions drive a lot of this, an understandable built-in zeal for tradition that comes from being dependent on metal filaments for the better part of one and a half centuries.

But I am largely concerned with concert design, so the synthesis of raucous and saturated colors is of particular import to me. Oh yes, give me your colors between the colors and every shade of incandescent blackbody emulation you wish – and I will pay for the privilege. But I also want a gold plucked straight from a summer sunrise, and a cyan bluer than any toilet bowl cleaner, and a magenta that Deutsche Telekom would sue you over. RGBW, however, never felt particularly great at reproducing these colors. It felt this way because is isn’t – in between your big tri-color spikes are deserts of spectral scarcity, which even the most untrained eye can discern, though unconsciously, as lacking.

Much work has gone into amber, and cyan, and deep red – parts of the spectrum still poorly-served by RGBW. Magenta is the outlier here, as magenta is an extra-spectral color that has no corresponding “single” wavelength – it’s a combination of red and blue wavelengths. The hard work shows, too – with the Source4 Series 3 deep red and indigo and amber and cyan emitters, I can make a truly delicious grape or vibrant rose color, or a fiery orange or a briny sea foam. Notably absent from the list of secondaries? Yellow.

Yellow is a tricky one. It’s difficult to produce with LEDs from a technical standpoint – whatever alchemy LED chemistry engineers do to discern the various elements or isotopes that will make a particular wavelength has been somewhat unfruitful, I am told, for yellow. Not totally, mind you, the chemistry itself does exist, but mostly in lab form where such LEDs remain under-powered and sadly somewhat under-researched relative to other colors. A high-powered phosphor-converted version could (probably) be made at scale, but the demand to fill the other gaps in the spectrum has been more urgent the last decade or so, as we’ve been trying mostly to create superior color rendering LEDs for houses and cars headlights. We weirdos in the entertainment biz are really the only people interested in having saturated colors anyway; mostly, people just want vanilla light. This is frustrating – when you compare the yellow you can get out of any LED system to that which you get from a subtractive system – especially an old-school gelled incandescent – it becomes apparent that you are glimpsing this color as though through a veil; a mere shade of the glory it can encompass. RGB yellow looks pale, sickly, weak. Even today, if I needed to get a deep banana or sunset yellow out of an LED fixture, maybe I’d dial up a calibrated white and put a gel in front of it, extracting the color I want from a full spectrum rather than relying on the red and green emitters4. Because I need that yellow. I crave it. The irony of saying I’d prefer subtractive mixing out of a PAR for one color is not lost on me, being on the record as being feverishly anti-incandescent, and I still am. I can accept this – I don’t think the benefits of LED are outweighed by not having a great spectrum for one slice of the rainbow, but I do find it nettlesome.

Various signs do point to a gradual improvement of the circumstances5. A higher percentage of lights newly on the market are upping their die color count relative to past attempts. GLP’s Impression X5, despite its moniker being highly suggestive otherwise, serves up four-color RGBL mixing. Vari-Lite’s VL5LED gives us RGBALC in a tasty VL5-like housing – initial reviews are favorable – and even the necrotic Strand Lighting has some RGBALC fixtures kickin’ around. Clay-Paky has the K-Eye, also with six colors. An important point bears raising here, and that is this: when I speak of the need for expanded color range fixtures, I’m speaking of a need that I see for a specific class of fixtures: moving head hard-edged and wash fixtures intended either for pointing at people, or creating big beamy looks in the air with haze, or painting color onto scenery or objects. Sometimes, a reduced spectrum like RGBW really is good enough.

I feel strongly that these expanded color range fixtures represent the way forward for the concert lighting industry. Undoubtedly, it will take time to totally divest ourselves of RGB(W) – there’s enough bric-a-brac rattling around in rental houses around the world that will keep powering up for years6 – but there’s always a need for low-cost wall washers or audience lighting or whatever application doesn’t require a spectral confetti cannon. I’m just wholly underwhelmed by the aggressive mediocrity of the RGBW fixtures I see these days. It’s not even the fixtures per se. Lots of companies are making these lights, and engineering them well enough – they’re solid workhorse lights I guess, and I don’t really have anything bad to say about them being what they are for the purposes they’re intended to serve. A spectrum can be good enough for the budget and use case scenario, and that’s whatever. But I want to see more innovation with our color systems and really move away from RGBW as the “default okay” color system that gets specified on shows.

I think the immediate response this might engender will take the form of a “diminishing returns” argument. I’m not wholly unsympathetic to that – rental houses in particular aren’t going to be crazy about buying six or seven or eight-color systems only a few years after investing in the new hotness of RGBW, and just to get to something that your average audience knucklehead won’t notice or care about. But I’m with Mike Wood on this one in believing that additive mixing is the way forward, and while I didn’t harp on this too much, I think people do notice, and excellence is its own reward7. To gain widespread adoption, we’ll have to fix these spectral inadequacies, of which yellow represents one of the Final Frontiers to be conquered. We’ll also have to figure out how to get more light out of fewer emitters while keeping things cool – no small feat there, either. You know, engineering.

My thesis: RGB is laughable at this point, RGBW only slightly less so, and RGBAL is the minimum needed for concert-grade color, and preferably RGBALC. Even that doesn’t fully cover all of what I’d like, but I’m unsure of the licensing / patent stuff that comes along with Indigo and Deep Red. (Why is only ETC using them? I dunno.) But even if we got to RGBALCIDe89 systems, we’d still be missing a crucial band in the yellows. If there’s a point to all this, it’s a plea for continued research into closing the yellow gap with some high-power phosphor (or direct10!) yellow LEDs to fill in the spectrum, so we can finally experience the full color range with all of the advantages of LEDs. Perhaps through the time-honored tradition of collective outrage, we can “encourage” manufacturers into giving us nine or ten-color color-mixing systems – but only if we get some intelligent algorithmic software to go along with it. That, however, is an article for another time. In the meanwhile, when I need deep yellow, subtractive will be the way to go.

  • 1 I am aware that there were others before, please don’t email me about this.
  • 2 The best reds came from the Martin MAC TW1 and the other halogen fixture that Bandit owned, the Coemar iWash Halo.
  • 3 Again, it probably wasn’t the first RGBW light, and I don’t care. It was the first one that I saw.
  • 4 Or use something subtractive. I’ll concede that this would be a specific sort of scenario.
  • 5 Except the new Zonda 9 from Ayrton? RGBW! Why!?
  • 6 Or maybe not, because if there’s a weak spot in nearly the entire LED entertainment lighting industry, it’s undersized, crappy LED drivers.
  • 7 Similarly, throwing up our hands and saying “They won’t notice, so who cares?” is a defeatist attitude contrary to the very idea of excellence.
  • 8 Red, green, blue, amber, lime, cyan, indigo, deep red.
  • 9 Gonna need a better name than this, too.
  • 10 Let’s get a chant going of “Dope! Dope! Dope!”

And, Why It Is Not Just Philosophical Navel-Gazing To Say So

This is a response to an article I most recently saw in PLSN, but in fairness to my friend and author of that article, Chris Lose, this is an argument I’ve heard put forward by many people over the years. The argument goes like this: color is a perceptual phenomenon, and therefore, “does not exist”. It exists, the argument goes, only in our minds, and this somehow makes it less real.

I find this line of reasoning to be highly suspect. It places all perceptual phenomenon on “non-existent” footing, including a lot of things that I think we would all agree exist, like smells, flavors, all of music, language, emotions…I could go on.

Briefly – because I think it will be helpful – let’s describe how color “works”. Light strikes an object, and some is absorbed, some is reflected, some might be refracted, and some will experience some strange quantum effects that won’t have any practical macro-world effects. (But which will be nonetheless cool) The reflected light will interact at an atomic or molecular level with whatever stuff the object is made of, and some of the reflected wavelengths, through that process, will be attenuated.

OR

Light is directly emitted by something – the LED subpixels that probably make up what you’re reading this on right now.

Either way, those wavelengths eventually enter your eyeballs, excite some rod and / or cone cells, send some electrical signals to your brain, then some hellawhack shiznit happens inside your brizzle and you see color.

The argument usually says that, because the color isn’t a physical thing that’s “out there” in the world somewhere, unable to be held in the hand or quantified in any way, that it does not exist. This argument hinges on a curious definition of “existence”, where something must have physical form, or at the very least, be able to be scientifically quantified. Color, the argument continues, doesn’t exist, but light, of course, does, and can be measured and quantified, and the various wavelengths that light comes in “trick” our minds into experiencing color.

The problem that I see with this argument is that ignores almost every subjective experience that human beings can experience. Music isn’t “out there” to be held in the palm of your hand, just vibrations in the atmospheric medium beating against your eardrums, causing similar electrical signals that cause the sensation of seeing. In the case of “music”, we use the term to describe several things: physical pieces of paper with symbolic writing to reproduce the music, but also the sounds of music themselves. Fundamentally, there is no difference between the experience of listening and the experience of seeing – both involve our brain’s interpretation of various frequencies of…whatever. Light, or oscillations in the air. And yet, most people would agree that music “exists”, despite our inability to hold it in our hands or quantify it in a meaningful scientific way. (Also see: any example of “contemporary classical” music.)

Further, I think it’s arguable that we can quantify color, as a physical process and (perhaps somewhat less accurately) as a perceptual process.* We can examine the wavelengths of light, and decide what color they are. Just because we have not sat down and mapped things down to the nanometer in terms of where red ends and orange begins does not mean that we couldn’t, just that there are better things to do with our time and we have only broad, but not specific, agreement on color terms. The science of spectrophotometry and colorimetry are based on quantifying reflected wavelengths and mapping human perceptions of wavelengths, most notable the CIE 1931 “half a colorful jellybean” chart you’ve probably seen a dozen times. We already break up the electromagnetic spectrum into waves of various sorts by defining where they begin and end – X-rays, gamma rays, etc. It’s a logical possibility that we could also quantify color names in this way.

As another example, take smell. Do smells exist? Taking the narrow definition of “existence” that we’re examining here, we would have to conclude “no”. Smells (and taste, for that matter) are perceptual phenomena that happen in our brain. A pepper does not smell or taste spicy. Pears do not taste sweet and pear-like. The pepper’s spicy-ness and the pear’s sweetness and pear-ness happen due to chemical compounds sending particular signals to our brain. Emotional states, and even body states, are another example. Does pain exist? Does happiness? Does ennui? Ask someone experiencing these states, they will certainly say they exist. And you likely would too, if you were experiencing them. And, on my account of existence, you or the people experiencing them would be absolutely correct in saying that they do.

Where the argument against color existing fails is an overly-narrow definition of “existence”, and perhaps a tendency toward an odd form of solipsism. (I don’t know that your red is the same as my red, and so forth.) We commonly agree that all sorts of perceptual phenomenon exist (the smell of a rose, the taste of a pear, the music of Beethoven) and there is no reason to exclude color from the common understanding of the word. Some of this argument relies on semantics – and most arguments of this sort rely on extremely precise definitions when we really examine their contours – but I think you’d be hard-pressed to find someone who draws such hard distinctions between things that exist physically and purely perceptual phenomenon**.

Color – like everything else we perceive – is generated by our minds, but – and this is important – typically corresponds to real physical things that happen in the world. So, we use the term color to describe the qualia of seeing and “decoding” particular wavelengths of light, just as we describe 440 hertz as the musical note “A”. To head off a related argument that I see sometimes argued in dubious YouTube channels, the same applies to the color magenta. Magenta exists just as much as any other color.

Here I want to move onto the second part of my counter-argument, and go a little bit further than saying that perceptual phenomenon exist in and of themselves. Color can also refer to the physical processes that produce the wavelengths in question, and in this sense, color also exists as a physical process.

For instance, if you were to look at a Monarch butterfly, you could say to me “The butterfly’s wings are orange.”, and this would be true. They have (or perhaps “generate” or “cause” are better words?) the color orange – there is a real, physical, tangible thing that’s happening at an atomic level that is causing some of the white light to be absorbed, and orange light (light in particular wavelengths that we call orange) to be reflected, and then a complicated thing happens in our brain and our eyes and we experience orange. The color is the process at the physical level, and it is also the experience that we have, and they cannot be cleanly separated from each other. I therefore submit that color exists in two senses of the word – both physically (it would exist whether we see it or not) and as a perceptual phenomenon that happens in our eyes and nerves and various cortices that contribute to the qualia.

Why does this argument matter?

Well, we have words, and those words have meanings that we should be careful and precise with. We have a word that, on my account, refers to the whole of the physical process plus the experiential phenomenon, and I think my account accurately describes the common understanding of what we mean when we say “color”. Saying “color does not exist” is something I think gets said for the shock value, because it’s so intuitively (and, I would argue, in reality) untrue. But – like the equally incorrect “magenta is a fake color” meme of the last few years – it doesn’t advance people’s understanding, it just gives people an incorrect understanding about an interesting perceptual phenomenon. I suppose in all charity it might spur someone to go looking into color theory and vision processes, but it’s just as likely to cause confusion repeated at a cocktail party by someone who doesn’t know what they’re talking about. It is the lighting designer equivalent of those “gotcha” jokes that hinge on the ambiguity of language to get a laugh.

Guys, color exists. This month, put up your pride / trans / whatever you fly flag, wear your most outrageously mageneta socks, and bite into the greenest of pears, and gaze at the most orange-est and red-est and yellow-est of sunsets you can lay your eyes on. And don’t let anybody tell you that the colors of all these things is anything less than totally real.

*There are interesting developments in mind / machine interfacing that might in the future make it possible to know if your red and my red and the same, and that’s very interesting.

**Of course, there are philosophical arguments regarding qualia, which is the philosophical term of art for mental states, and also philosophical arguments about existence and maybe we’re all just brains in vats or potatoes floating in space, but these arguments are beyond the scope of this already somewhat philosophy-flirtatious article.