What is bias lighting and why do we hear that it should be high CRI with a color temperature of 6500K?
Bias lighting is a source of illumination that emanates from behind your display, improving the perceived performance of your TV or monitor, by providing a consistent reference for your eyes. (I’m not talking about novelty colored LED lights that turn your living room in to a disco).
What does bias lighting do?
Proper bias lighting brings three key improvements to your viewing environment:
- Firstly, it reduces eye strain. When watching in a dark environment, your display can go from a completely black to a very bright scene many times during a show or film. The pupils of your eyes need to rapidly adjust from total darkness to this bright light and, over the course of an evening’s viewing, you can suffer significant eye fatigue. Bias lighting ensures that your eyes always have a light source in the room without detracting from, or reflecting off, your display. This is one of the reasons bias lighting is practically a necessity for any OLED television, which are capable of extreme blacks, and any HDR set, that is capable of high luminance
- Secondly, bias lighting improves your display’s perceived contrast. By providing a lighter reference behind the television, the blacks of your display appear blacker by comparison. You can see exactly how this works by looking at this diagram. The grey rectangle in the middle is actually one shade of grey, but as we lighten the area around it, our brain perceives it as becoming darker.
- Finally, bias lighting provides a white point reference for your visual system to balance on-screen colours to. By offering the closest and most consistent reproduction of simulated D65 white, the MediaLight is by far the best product on the market to achieve high color acuity.
The MediaLight is a collection of industry-leading ColorGrade™ LED lights on an adhesive strip, that offers a simple and powerful bias lighting solution for any application. It is easily installed within minutes and, in most cases, powered via your television’s USB port, meaning the MediaLight will turn on and off alongside your television automatically. This makes the MediaLight a “set and forget” installation and, when you consider that all MediaLight bias light strips are backed by a five year warranty, means they are easily the best value upgrade you can make to your home entertainment environment.
But it’s not just for home theater applications - the MediaLight is used in professional color grading environments too. In fact, the MediaLight family now includes simulated D65 desk lamps and bulbs that all feature the same 98 CRI and 99 TLCI ColorGrade™ Mk2 LED chip as the MediaLight strips, and are backed by a three-year warranty.
You might think that OLED doesn't benefit from bias lights, but you'd be incorrect. Because of the better black levels and extremely high contrast ratios of OLED and Micro LED displays, eye strain is a bigger concern.
You say you don't experience eye strain? The perceived brightness or darkness of a display can still be enhanced and the contrast is still boosted, regardless of the capabilities of the display.
In the following image, we present two white squares in the center of of a black plus sign. Which one looks brighter?
They are both the same, and both are limited by the maximum luminance of your display.
However, if you said that the white square on the left looks brighter, you've just experienced how bias lights boost contrast. Many people mistakenly believe that bias lights only improve shadow details. Now you can prove them wrong. Bias lights enhance perceived contrast through the entire dynamic range -– not just shadows!