By Gary Feather
Display specifications can confuse even the sharpest of audiovisual (AV) insiders. With short-hand abbreviations, easily confusable acronyms, and frequently inconsistent definitions across the industry, it is important to make sense of all the jumbled jargon floating around. One such specification that often puzzles signmakers is white point.
One may have noticed how their mobile phone changes the tint of the display screen from a crisp blueish light to a softer beige glow once it enters night mode. What the phone is doing is adjusting its white point in response to the change in the user’s environment. Modifying the white point setting in this example eases strain on the user’s eyes, but it can also be used to change the mood of the content. One can think of it like an Instagram filter for the display.
That said, what does white point mean? How does it work in practice? What role does it play in display performance? It is important for signmakers to understand the specifications of a display solution to figure out how best to use it to engage their clients’ audience.
What is white point?
White point is the term used to reference the appearance of white on a screen or surface. It is also known as colour temperature. By simply noticing how one’s phone changes its white point at night, they can see the colour ‘white’ is not always ‘white.’ Theoretically, a true white does exist, but it is not something one sees in everyday life. Objects one knows as ostensibly white, such as a piece of printer paper, or device screens on phones, computers, or digital displays, have their own varying levels of off-white. These tints are simply referred to as white because it is easier to remember than to refer to the colour of the printer paper as Lavender Blush. In any case, the white level on a piece of paper is dependent on the environment it is in since the object itself is only reflecting light. The paper is always ‘white,’ but that colour looks different in sunlight than it does indoors. The white levels on static surfaces only reflecting light adjust based on their light environment. That said, the printer paper itself has no control over how it is seen. A light-emitting diode (LED) display, however, which creates its own light, has a white level that users can adjust themselves. Where one chooses to set this level affects the appearance of the display’s entire colour profile, as a blueish-white point will result in cooler blueish content, while a softer reddish-white point will result in softer reddish content. These levels of white, which are specified as white points, are measured in degrees Kelvin (K).