Until recently, the maximum affordable display resolutions still allowed comfortable viewing of all materials with little planning. The rapid adoption of high- and ultra-high definition displays means we must now consider content more closely.
- Applications like PowerPoint, image viewers and similar maximise the content to fit the screen – this is scaling and is entirely transparent to the user.
- Text- and line-based applications generally present exactly what you tell it to, and will not second-guess you to improve your presentation.
Consider a typical spreadsheet. First a screen grab at 1080P
and exactly the same document but at UHD (“4K”) resolution
A great deal more information is presented, but assimilation is much more difficult – if you were reading from any distance it may be impossible. Excel – along with word processors and most mathematical/scientific/engineering modelling programs – is a non-scaling application. Unless magnification is applied at ‘desktop’ level, everything is rendered at native resolution.
For text, if you ignore the white space above and below the character (defined by the author of the font) typical fonts appear to be at one pixel per point – so an 11-point letter will appear as 11 pixels tall regardless of the resolution you select.
At 1080P, that 11 pixels equates to just under 7mm tall on a typical 55” display, but
- Around 10.4mm tall at 720P but
- Only 3.5mm tall at 4K
Always consider unscaled applications when designing your display systems – regardless of the native resolution of the display, you should externally scale your ‘system’ resolution to a value that still allows users to navigate the desktop and viewers to read some content! User-applied magnification may still be appropriate, but at least you can read enough to start work!
There is no standard for the ‘system’ resolution; different institutions set it based on local factors. Many users are content with 1080P though some will select lower.
Contemporary routing systems may allow you to change this scaling ‘on the fly’ so you can trigger a change to 4K for DVD playback or back to your default for unscaled text. You should test this with a variety of source devices before considering deployment to live sites.