LED projection the right way

Posted by Bob Williams

Light Emitting Diodes, or LEDs, are set to revolutionize projectors. The reasons are many-fold and include: long life, high reliability, infinite contrast, low energy consumption, and no hazardous substances. But the biggest impact to actual projected picture quality is the color saturation created from these pure light sources.

LED’s unique color saturation means brighter and deeper colors than ever before possible in a consumer product. The way color scientists picture this impact of brighter and deeper colors than previously available is with a diagram called a CIE chart, where the deepest colors of red, green, and blue are plotted against a field of all possible colors that can be seen. When an LED projector, such as the Runco Q-750, is put up against best-in-class lamp based projectors, the resulting area, or “color gamut”, is 90% larger. That means 90% more of all visible colors can be seen when you use LEDs as your light source than if you use a lamp.

Of course, as a famous comic book once said, “With great power, there must also come great responsibility,” and this is also true when you have a large color gamut like this. Because as color scientists also will point out, the color gamut produced by the display should match the color gamut of the capturing device (film, video, etc); otherwise you will get exaggerated effects such as sunburned-looking skin and neon-looking colors. Literally, the colors will appear to be inside of the objects and lighting them up. So here at Runco, once we decided that LEDs were ready to go into our projectors my first thought was that we needed a way to control these vast colors in a way that allowed display of the vast color pallet without this issue, but was also user friendly and flexible enough to please everyone, including outdoor sports fans (who need the brighter colors) and video purists (who need accuracy). The result is our Runco Smart Color (RSC) and the Personhral Color Equalizer (PCE).

Runco Smart Color is a hue correction curve and color gamut mapping algorithm that prevents colors sensitive to the human eye, such as skin tones, from appearing the wrong hue, over-saturated, or over-bright. When enabled, you can safely use the entire color gamut of the LEDs without worrying about how well-matched the capture device is to the display.

The Personal Color Equalizer works like a graphic equalizer and adjusts all of the parameters needed to produce any color gamut that you desire. The PCE controls use easy to understand terms such as hue, saturation, and level, so you can feel free to experiment. In addition to the controls themselves, we have 5 presets that represent nearly all of the industry standards for the capturing devices. There are lots of fancy names like SMPTE C and DCI, so there’s an “auto” setting as well that will correctly select the right one for almost all sources.

So to sum it up, we at Runco want to make sure that any technology we throw your way, no matter how promising, is enabled in a way that allows you the maximum enjoyment as well as the ability to tailor it to your needs. We believe we’ve done so for LEDs with our Runco Smart Color and Personal Color Equalizer.

Bob Williams is the Chief Product Architect for Runco International. He has worked on digital projectors for the past 15 years and lives near Portland, Oregon.