Since 2013, 4K resolution has been made available in high-end TVs but for the moment it is accessible only through satellite channels or through special media-players, with a built-in hard disk or solid-state-disk, where 4K content may be preloaded at factory time and more content can be downloaded from suitable network or cloud servers before watching. It is worth mentioning that 4K is the resolution of digital cinema (though, this comes at 24Hz frame rate) which is gradually spreading in theaters equipped with facilities for secure and DRM-protected downloading of movies, normally via satellite.
The 8K resolution is currently available in prototype displays and can be enjoyed only with content from shooting experiments. At the moment it is visible only on the occasion of demos, trade shows and events.
The UltraHD is not only a matter of spatial resolution (number of pixels) of displays, it is also about greater color depth, higher temporal resolution (number of frames per second, not more than 25 or 50Hz of the HD, but also 100Hz and over). Audio experience comes with a very high degree of viewer’s involvement, being supplied by a system of 11 or 22 channels.