In recent years, with the widespread use of solid-state LED lighting fixtures, many people are also trying to analyze the complexity and control methods of LED color technology.

About Additive Mixing

LED flood lamps use multiple light sources to obtain various colors and intensities. For the entertainment lighting industry, adding and mixing colors is already a clich é. For many years, practitioners have used lamps with color filters to project the same area on the canopy, which is not easy to control. A spotlight with three MR16 light sources, each with red, green, and blue filters. In the early days, this type of lamp only had three DMX512 control channels and no independent strength control channels. So it’s difficult to keep the color unchanged during the dimming process. Usually, computer light programmers also set up a “light off color change” to easily turn off the lights. Of course, there are better ways, and I won’t list them all here.

Control and Definition of Colors

If the user does not use pure DMA values to control intelligent lighting fixtures, but uses some abstract control method, a virtual intensity value can be used. Even if the manufacturer specifies that the lighting fixtures use three DMA channels, the abstract control method can still be assigned four handles to control: intensity value and three color parameters.

Three color parameters “instead of red, green, and blue, as RGB is only one way to describe colors. Another way to describe it is hue, saturation, and luminance HSL (some call it intensity or lightness, rather than brightness). Another description is hue, saturation, and value HSV. Value, also known as brightness, is similar to Luminance. However, there is a significant difference in the definition of saturation between HSL and HSV. For simplicity, in this article, the author defines hue as color and saturation as the amount of color. If ‘L’ is set to 100%, it is white, 0% is black, and 50% of L is a pure color with a saturation of 100%. For ‘V’, O% is black and 100% is solid, and the saturation value must make up for the difference.

Another effective description method is CMY, which is a three primary color system that uses subtractive color mixing. If white light is emitted at first, then two color filters can be used to obtain red: magenta and yellow; They remove the green and blue components from the white light separately. Usually, LED color changing lamps do not use subtractive color mixing, but this is still an effective way to describe colors.

In theory, when controlling LEDs, it should be possible to adjust the intensity and RGB, CMY One of HSL or HSV (with some differences between them).

About LED color mixing 

The human eye can detect light with wavelengths ranging from 390 nm to 700 nm. The initial LED fixtures only used red (approximately 630 nm), green (approximately 540 nm), and blue (approximately 470 nm) LEDs. These three colors cannot be mixed to produce every color visible to the human eye