Optimal picture size for viewing HD and 4K at different distances at home
When you deciding which TV to buy, manufacturers talk about the right screen size for the distance at which you watch the picture. This is based on the image taking up at around 30º of your field of view – this allows for less distraction from outside the TV picture area and allows for people with 20/20 vision to get the benefit of HD resolution – to see pixel-level detail.
To get the benefit from the larger number of pixels in 4K TVs and displays, suggestion is the image should take up around 60º of the viewers’ field of view. This is based on 20/20 vision being defined as being able to distinguish detail at 1/60th of a degree of your field of vision.
Here is a table showing the optimal diagonal screen size for HD and 4K images at different distances [Using this field of view equation]:
In the UK I don’t think that typical homes have got bigger in recent years. Most people set up their TV and seating to fit the room layout. A 2004 BBC survey reported that the average TV viewing distance in the UK was 2.7m (8.9ft).
Following the 30º recommendation, the best HDTV size for the average viewing distance would be 70″ diagonally. For 4K, the image should measure around 136″ diagonally.
For now if you want a 4K experience at home, I suggest you investigate projection systems.