Raziel123 on 19 July 2014
and I forgot to add:
A 50" screen with a 16:9 aspect ratio is about 43.579 inches (1.112m) wide by 24.513 (0.623m) tall.
At 1920x1080, the pixels would be 0.0227 inches (0.579mm) wide and tall. At 1280x720, they're 0.034 inches. (0.864mm)
The typical resolution for a human eye with 20/20 vision is about 2 arcminutes per line pair.
This means a feature is no longer resolvable when it's 10,801 times further away from the eye than it is tall/wide. (2 arcminutes / 360 degrees = 10801.08)
On a 50" display with a 1080p resolution, individual pixels can no longer be resolved if the viewer is 20.432 feet (6.228m) away from the screen. For the same display at 720p, it's 30.603 feet (9.328m).
