Originally posted by richandfleur Previously, as TV screens got bigger, the resolution didn't, so you just ended up with fatter pixels.
From the same distance back your TV ended up looking lower resolution as it got bigger.
4K means that you keep the pixel size/density of say a 32" or 40" TV when you expand the screen size to 60" or so.
In practise, if you can feed it with a real 4K source (of which youtube for instance now offers quite a bit) you WILL notice the difference and it looks superb.
Not quite true. There is an optimal viewing distance for a given screen size, in order to create the optimal FOV with respect to the eyes.
In other words, if you have a smartphone, bring the screen close to your eyes. If you are at the cinema, don't sit too close or you will feel nauseous and you won't be able to process the entire screen at once.
It is possible to show that at the optimal viewing distance/angle/screen size, it is not possible for a person with average eyesight to really see a difference between Full HD and 4K (UHD). So the extra resolution is "wasted."
Most people who are awed by a 4K screen are looking at it from too close a distance for optimal viewing.
Indeed, for some of us who are a little bit older, we may even find it hard to differentiate between SD and HD. I use to laugh when someone told me they can't tell the difference between upscaled SD and HD, now I am not laughing any more because I have the same problem.