Brightness

If a display is too bright it can cause eye strain. And many displays are too bright. Bright displays can be ideal for signage and shows, for example, but they can damage user experience in working environments.

Our eyes are like cameras. They adjust to varying light levels with muscular effort. If the key objects in clients’ spaces vary too much in brightness, this is the equivalent of optical weight lifting. Result: eye strain and reduced productivity.

There is absolute agreement here within building and lighting standards, from decades’ old guidance from CIBSE (Chartered Institute of Building Services Engineers) and the Society for Light and Lighting - and now to the bang up to date WELL V2 well building standard. The metric used is called Task Luminance Ratio (TLR) and there’s a number, agreed by all. 3:1. Three to one. So what does this mean? It means two things.

Firstly, it means that all the main objects (or ‘tasks’), such as screens, papers, table, people etc) should be within a luminance (brightness) range so that the brightest is no more than three times brighter than the darkest. This avoids forcing your eyes to make continuous large adjustments.

Secondly, it means - paradoxically - that the black levels in your image are more important than the white levels in your image. Why? Well, if you don’t want the image too bright, this means there’s a limit on the required white levels. Therefore if you want good contrast you have to focus on the black levels.

So if that’s the theory, what does this mean in practice?

With flat panel displays, this means making more critical judgement in your choice. But pay particular attention to how shiny the screen is because this is the classic way of creating ‘cheap seats’ in AV-enhanced spaces - without even trying!

With projection this means using ALR (ambient light rejecting) screens, the global leader being our screen of choice, the pioneering dnp Supernova, of course! And using these screens means you have a completely matt surface, delivering the ideal viewing experience.

Seeing is believing. Clients with larger budgets need to know they are deploying their budget well. Set expectation levels and get them to buy in actively to selection process by setting up demonstrations in their proposed locations. The Visual Displays team is here for you. Request a site Survey here.