Welcome Selador to ETC - a new home for the x7 color system

My name is Rob Gerlach.  I am one of the co-founders of Selador.  Today we announced that ETC has acquired the Selador LED product line.  This is, of course, a really big day for me and fellow co-founder Novella Smith, but I think it’s also a big day for our industry.  Things are going to change a lot because of this.  That sounds like a PR-approved message, but I truly believe it.

We all know that LEDs are all over the place.  Go to any trade show, and you’re bombarded by them, and I get as sick of the hype as anyone else.  Yes, they’re a great technology.  The power savings and longevity and durability they can achieve are in a whole different league than conventional lighting.  But in my mind, these benefits kind of miss the point.  For me, the truly wonderful thing about LEDs is that they are absolutely beautiful little light sources that can do things that no other lights in the world can do. 

This inherent beauty is what drew me to LEDs in the first place.  I wasn’t a lighting person before starting Selador, but when I saw how LED technology was changing about 10 years ago, I became obsessed by it.  LED color is spectacular.  It’s deep and vibrant and controllable with a level of precision that designers could only ever dream of.  To see the difference between LED color and color from a standard source with a saturated gel, look at the following two graphs. If you have a lighting background you will easily recognize the visible spectrum of light within these graphs with Violet at the far left and Red at the far right.

 

You’ll see that not only does LED color have a much narrower spectral footprint, it is also more cleanly defined.  Where many gels will have multiple peaks of color of various widths at various points in the spectrum, LED color always has just a single, narrow peak at its dominant wavelength.  On its own, this characteristic is neither inherently good nor bad.  The trick is that in order to be really useful, especially when adding multiple LED colors together, this color has to be managed in the right way. 

There are shortcuts to color mixing.  Red, green, and blue (RGB) can get us kind of close, and this approach is fine for many applications, but it’s a weak substitute for real color control in those situations where the quality of light is critical.  Here are some more graphs:

     


Some marketing materials like to throw around the term “Full Spectrum” when talking about color-mixing LED luminaires.  Clearly from the above graphs, it can be seen that color-mixing LED fixtures are not full-spectrum sources, particularly RGB fixtures.  Even with the seven colors we use in the x7 color system, there are peaks and valleys.  The x7 approach has far more spectral content to work with which is one of the big advantages. I think it is unlikely that a color-mixing LED fixture will ever produce light that exactly matches sunlight’s spectral power distribution (sunlight is a truly full-spectrum source.)  However, with the proper management of the various colors in the mix and their brightness relative to one another, the output can be made close enough to full-spectrum to be broadly useful and very beautiful.

Many people have seen these next two diagrams.  The first diagram at the right shows the color capabilities of a typical RGB fixture.  When you only have three points of color within an additive color-mixing fixture, the range of color that the fixture can produce can be defined by plotting the three colors on a chromaticity diagram and connecting the dots.  Everything within the connected dots is that fixture’s color gamut. 

  

 

 

 

 

 

The second diagram shows the Selador x7 system color gamut.

With seven points of color, the fixture’s color gamut covers a much larger part of the chromaticity diagram.  After years of research, Selador was able to show that the more colors there are in an LED light source, the more saturated and vibrant the color mixes are.  We also showed that this multi  -color approach produces the most satisfying, natural-looking white light and soft pastels, particularly when illuminating people and objects.  In order to make skin tones and colored objects render correctly, you need lots of points of color within the color mix—basically you want to reduce the magnitude of the peaks and valleys in the spectral makeup, smoothing them out somewhat by adding more colors across the spectrum, and match the spectral power distribution of sunlight as much as possible.  Without this, LED fixtures don’t work very well in conventional illumination functions.  RGB light does very odd things to skin.  It always produces pink / ruddy or greenish-gray skin on people, which I imagine is not generally a desirable thing.  Colored objects under RGB light look unnaturally red or green or blue—the objects’ colors are hyper-real and difficult to tell apart from one another.  Hence Selador’s unique seven-color system.  It’s the only way I’ve ever found to get LED-based lighting that is predictable and intuitive, that does natural things to people and objects, and that doesn’t have that obvious, electronic look to it that I despise.  It is also very rich and appealing to the human visual system, which over time has evolved to be deeply connected with the full-spectrum light we see each day from the sun.

There are other components of Selador fixtures that are critical for them to look natural to the eye and seamless next to conventional fixtures in a rig.  Selador fixtures have newly redesigned circuitry within them that allows for exceptionally smooth, analog-looking dimming.  I have to say that this was surprisingly difficult to achieve with a light source as responsive and non-analog as an LED, but I am extremely pleased with the results.  Selador is also known for terrific beam-shaping capabilities.  No, we don’t yet have a Selador ellipsoidal (it will come) but the fixtures we do have can be shaped very nicely with specialized secondary lenses.  We get a lot of compliments about this.

Among a whole list of things, ETC brings to the table a ready-made world of control.  I know that seven-color mixing can be daunting.  Within an ETC system, it’s all simplified.  ETC makes Selador color mixing quick, intuitive, and predictable.  In fact the latest software for the Eos and Congo control systems already allow designers to control the Selador fixtures by calling up gel colors. The fixture libraries in these systems are calibrating and I have to admit the color matches are very good. I’ll discuss this in more detail in a later entry.  I’m pretty excited about it.

There are many more things we plan to do.  With ETC taking over, our combined efforts can now produce new products and introduce enhancements that have been on the drawing boards for a long time.  There is exciting stuff in the pipeline, and I’m very happy that I get to be a part of the development team at ETC for new Selador series products.  More to come. . .

Published 02-16-2009 8:00 AM by rgerlach
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