Did you know? #33 - Let's talk about white

On the basis of the introductory words to this "Did you know?" it is surely already clear to you that the topic with the color white is not just dealt with. From a technical point of view, white is not a color, but a mixture of several (spectral) colors. For the sake of simplicity, however, we will stick to the term that white is a color.

Those of you who are ambitious photographers or who also like to work with (video) cameras, surely already have a (pre) idea where the journey is going. Because also in the show and especially in the theater sector the topic white plays a very big role. A simple statement "make it white" is therefore by no means precise enough to fulfill the "wish" of the "client" completely to his satisfaction. In addition, there is the question how DMXControl 3 can support you at this point to achieve the desired result quickly.

White = white?

As is well known, there is not only one white available. White can be reproduced in a multitude of nuances. In common parlance, you're probably familiar with "cold," a more bluish white, and "warm," a more yellowish to orangish white. Anyone who has bought LED lights for their own four walls has certainly already come into contact with these statements or has also seen associated numerical values on the packaging. These are usually four-digit numbers followed by a "K". The numerical value here stands for the value of the color temperature, to which the unit Kelvin (K) is assigned.

By definition, low values below around 3,300 Kelvin are assigned to warm white and values above 5,300 Kelvin to daylight white or cool white. You can take the additions warm and cold literally, because a warm white creates a much greater atmosphere of well-being and comfort than a cold white. This applies not only to your own four walls, but also to shows. Within shows, the mood can be transported to the audience by the color temperature alone. A scene that takes place outside on a dark and rainy autumn day looks all the more uncomfortable if this scene is also illuminated with a very cold white. This makes the skin of the actors and actresses and also the surroundings look very pale. However, if the actors come together at a campfire, a rather warm illumination is appropriate, which the audience and you yourselves can see well on the entire stage. The entire stage radiates a certain warmth towards the audience. In the following three pictures you can also recognise the influence of the color temperature to the whole scenery.

Illumination of the scenery in about 3.000 K Illumination of the scenery in about 4.500 K Illumination of the scenery in about 6.500 K

How does the white get on stage?

Another aspect of the color white is what fixture you use to bring the white into the show. Until a few years ago, classic spotlights with a halogen bulb or even a discharge lamp were considered the standard, especially when it comes to brightness. But now there are (almost) equal headlights based on LEDs in the entire price spectrum. With LEDs as a light source, you're probably asking yourself the question: can I also use them to create a good and "beautiful" white? The answer is: in the meantime, yes. Since you can use more than three colors (red, green, and blue) per LED chip and create light with a full color spectrum by combining several colors, LED spotlights are indispensable for stage lighting.

So that you as an outsider can now judge how "good" the artificially generated light is, you will increasingly find the indication of the color rendering index - CRI for short - on many devices. As the name suggests, this indicates how close an artificially generated light comes to that of the sun and thus looks increasingly natural. This is because, as can be seen particularly often with a rainbow, the light of the sun does not consist of a single white but is composed of all the colors of the color spectrum. That is why we spoke at the beginning about white not being a color in its own. LED spotlights first had to reach this level. The better the LED spotlights succeed in doing this, the better the CRI value, whereby the maximum value of 100 is assigned to sunlight as natural light.

Illumination only with the RGB colors of the spotlights At the latest now you should be aware why a good white can be produced much better with an RGBW spotlight than with an RGB spotlight. If RGBWA LEDs, i.e., LED chips with five or more different colors, are used, this works increasingly better. In all cases, however, the optics are important. A not so optimal optic contributes to the fact that the white illumination with the simple RGB spotlights is rather spotty and especially the human skin appears unnatural. With each additionally installed color, the color spectrum (i.e., the rainbow) is directly supplemented by the light source, whereby there are, for example, significantly fewer "dips" in quality during the transition from red to yellow to green - because precisely the yellow in RGB devices can only be mixed from red and green, while in devices with an additionally installed amber "fills up" this area between red and green. This applies equally to white: The more uniform the color spectrum, the better the color rendering index and the better a good white can be produced - often then even in a wider range from warm to cool white.

For the sake of completeness, it should be mentioned at this point that white LEDs with different color temperatures do not necessarily have to be installed for good white. LED spotlights with the colors red, green, blue, amber, lime and cyan can also bring a very good white onto the stage. The secret behind this is on the one hand, of course, the optics, but on the other hand, the specific matching of the different LED colors. Their spectra then often merge very smoothly into one another, so that in total the entire color spectrum can be reproduced.

Support by DMXControl 3?

Now you surely still ask yourselves the question, what has DMXControl 3 to do with the generation of the white? That is all "pure" hardware? This is correct of course. DMXControl 3 has no influence on the result, what the LED fixtures are able to do or not. But DMXControl 3 supports you in selecting the white. If LED chips are used in your devices, which can generate at least two different white tones directly according to our current definition, the additional entry for the color temperature appears in the device control. The HAL in DMXControl 3 is responsible for this, if it finds colors like amber, warm white, neutral white or classic (cold) white in the DDF.

The value for the color temperature is then set to 6,500 K by default, which means that when selecting the color white, primarily only the classic (cold) white LEDs are used. You can use the corresponding slider to select a warmer white, as long as the color remains unchanged at the default value 1; 1; 1 or 255; 255; 255. You can also add a fanning to this value as you can see in the picture. In the background, the program will linearly sweep back and forth between the different shades of white that your device brings along. This automatically results in the possible range of values. The more different white tones are available, the finer the gradation is, of course. On the other hand, the HAL also goes further and offsets the set color temperature with the selected color. This should also be mentioned here for the sake of completeness. Thus, you can select the right white very quickly within the scope of the possibilities of your used devices.

As already mentioned, you can also work with RGB or RGBW spotlights with a virtual color temperature. However, DMXControl 3 does not support this feature yet. If you should miss this feature after reading this "Did you know?", we would be pleased about a corresponding entry in the bug tracker - which may be provided by all following readers with appropriate comments or simple votes.

By the way: some devices offer different white colors as a predefined color. Now one could get the idea that here also the point color temperature applies. But in the context of DMXControl 3 these are also colors on a virtual color wheel. At the moment, you have to select these colors manually. Starting from the coming major version of DMXControl 3 there is a small extension in the area of the DDFs. With this you can quickly add these predefined colors to the DDF and then simply select them in the device control or in the color picker.

If you need more detailed information

If you want to read a bit more about the terms mentioned above, you can find more information in the "big" Wiki under the following links:

Now you know

This issue of "Did you know?" is - as you probably noticed - a bit different than the last issues. Of course, DMXControl 3 was not completely unmentioned here. But from our point of view, it can be quite helpful in some places if you look beyond the edge of your nose or better said beyond the edge of your screen together with us - especially if you use DMXControl 3 in the area of theater performances or musicals.

Your :dmxclogo DMXControl Team :dmxclogo