Control Room Display Wall: How To Pick The Suitable Brightness

In a 24/7 control room, the displays must be clear, readable, and crisp. Therefore, the operator's comfort is the main goal as they make informed mission–critical decisions. The Control Room Video Walls are used to share real-time information among the operators. However, the demands on a control room display are very high. They must be comfortable for the operators to view all day, every day, as they shift their eyes constantly from their monitors to the display and the material on their desks. Therefore, the optimal brightness of a control room display wall is significant. 

Here is what to remember when selecting the appropriate brightness for a control room display.

Brightness Differentials

The human eye is great at adjusting between different light levels but poor at perceiving those differences. Naturally, to notice a difference in brightness, the variation must be significant; for example, people can see a display measured at 400 nits and measured at 700 nits. You would need to increase the brightness to almost 1000 nits before people agree they can see it brighter. For comfort, the operators in a control room should set up the display wall so that it's 2 to 3 times brighter than the light reflecting from their local monitors. This way, the display wall will stand out but not to an uncomfortable degree. However, the operators' position in the control room can vary relative to the screen's brightness.

Pupil Dilation and Operator Comfort

Your pupil dilates with changing brightness without even you being aware. This is because lighting levels tend to be similar within a given environment. But if you adjust suddenly or often, it is very uncomfortable. This is the same case with the control room. If the brightness of the display wall is too much higher or lower than the brightness of the operator workstations, the operators may experience eyestrain and overall fatigue. In addition to that, they may experience headaches or shoulder or neck pain. When this happens, a reduction in productivity and the benefit you expected from the display wall will not be produced. 

The solution is to match the brightness of the control room video wall properly to the room lights and the operator's local displays. It is essential to have a moderate level of light in the room. When the operator moves their eyes position between the monitors, the video wall, and surrounding walls and surfaces, brightness variations are minimized. Before you do that, you need to understand how to measure the brightness of the displays and the room. Brightness can be expressed in several units, lumens or ANSI lumens. This is appropriate for the output light bulbs and projectors but not display walls. But by expressing brightness in nits, you incorporate all the factors that make up the final image.