When we moved from standard definition to HD, I was very happy.  There was a noticeable improvement in image quality.  With SD, pixels were sometimes visible and images were soft.  HD provided far better resolution.  When we moved to 4K, I was a little confused because, although we definitely were rendering many more pixels at 4X the render time, the improvement in image quality often did not justify the extra cost.  It just wasn’t a big enough improvement in many cases.  Now 4K is roughly double HD (or exactly double if we are talking UHD) which means 4 times the pixels.  On the surface, this seems to make sense.  It would therefore follow that 6K, 8K and higher would be better…until you realize human vision is limited to the perception of about 3000 lines on the big screen.  At a certain point, pixel size reduces beyond human perception, at which point increased resolution is moot.

Please view this excellent discussion on the topic by Steve Yedlin, ASC who goes into significant technical depth on this subject.  This is a must see for any serious VFX artist or TD.

http://yedlin.net/ResDemo/#

copyright Nicholas Boughen 2017