Resolution has been advancing continuously since the early days of analog television. The latest incarnation is 4K displays, but even higher resolution devices are possible. In this article, we take a closer look at the science of visual acuity, along with when higher resolutions are beneficial to the viewing experience.
BACKGROUND
Our perception of detail depends not only on the smallest features in a subject, but also on the distance at which these features are observed. Human vision is therefore typically described in terms of angular resolution:
Being able to resolve lines in characters that are separated by one sixtieth of a degree (an “arc minute”) is the goal when testing eyesight. Since this resolution is typically assessed using an eye chart at a distance of 20 feet, this level of performance is defined as 20/20 vision. Similarly, 20/50 means one can only resolve detail that someone with 20/20 vision could resolve from 50 feet away. Alternatively, with the metric system these are all standardized around 6 meters and referred to as 6/6 vision instead.
Read more at Red.com.