Angle of eyes may be different and I'm more skeptical of whether we can tell if people really are looking at us off-angle or from considerable distance.
On the one hand, we're certainly hyperaware of faces both in central and peripheral vision, as part of our brain is dedicated to face detection, and eyes have high contrast (black on white). And looking dead-on at someone's eyes we can infer where they're looking even from pretty far away. All of this of course serves a social / evolutionary / survival purpose.
On the other, it may be that peripherally all we can tell that someone's is facing us and has open eyes, and this leads us to have a premonition that someone is looking at us. When we look up to confirm, this may or may not be true, but we'd be more likely to remember/encode that they were, thus making that sense err on the side of assuming people are looking at us. Add to that our own sudden shift in the angle of our face/eyes, which may cause them to react and look our way. We also don't get confirmation of whether people far away are looking at us, or if they're looking at someone next to us. Thus we don't really know if they are.
For me, both of these situations (thinking they are looking at me and finding they aren't, and seeing people look at me in response to my looking their way) happen frequently. I'm not sure our senses are that good at off-angle 'who's staring at me' though; instead I think we're just really well optimized to assume that just in case. Our brain is phenomenal at filling in the blanks visually, and making inferences based on important survival signals like where others are paying attention.
https://www.blurbusters.com/blur-busters-law-amazing-journey...
I mean, the blur there is very slight, but still!
The error in reducing the fps to that of the human eye is that there is no guarantee the two are in sync. To guarantee I will actually see 72 fps (or x fps) as intended, the manufacturer needs to take into account the amount of time each frame is displayed, as well as the human response to changing frames on the screen during one "frame" of the eye. How many times should a pixel refresh during one observation to create a lifelike scene for the human eye?
Something analogous can be said for dpi, and the fact that we can't see a specific pixel doesn't mean that each of our eyes' "units of resolution" correspond perfectly to where a pixel is on the screen. If we are seeing the intersection of four pixels at once but only seeing subpixels of each one that don't correspond to the intended color when taken together, theoretically all the color is falsified. If we are instead seeing a number of complete pixels in each of our own visual pixels, there is less chance of this. Further, the spacing between pixels varies by manufacturer, and this can have effects on the required resolution.
The same is true of visual resolution. You only have high resolution sight in a tiny portion of your vision, the rest is much lower resolution and your brain uses a combination of rapid eye movements and spacial memory to fill in the blanks.
Additionally one of the issues with perception of a pixel is your eyes have nothing like a pixel grid, it’s pretty random. You can see this if you use a digital camera to take a photo of a screen, you can see interference patterns as the grids align and unalign.
This makes the whole equation very complicated, certainly nothing I can answer. I guess I’ll have to find an 8k/120hz display and find out.
It was pretty easy to set up a blind trial with 5 monitors by putting cardboard around the monitor bezel and stand, and asking people which one looks better.
Everyone, even nontechnical people such as HR and sales, can identify the 4k monitors, super reliably, at a distance waaaay beyond what optometrists claim should matter.
Of course you could argue that the experiment was confounded by backlights or color calibration or monitor age whatever. But IMHO the result is so stark that it would easily survive even if you repeated the experiment with a bunch of identical 4k monitors, and set some of them to crappy low resolutions.
You can also perceive very high frequency lights by the strobe effect. For example if you wave your hands in front of a PWM LED or a bad fluorescent light you can quickly tell. By moving my eyes quickly from left to right, I can easily spot the order in which my office projector flashes the colour components of its image.
I do think there are some possible edge cases where 4K might not be good enough, even in the parent's reference example for possible worst case scenario. But we could have 5K or 6K. Going 8K takes ridiculous amount of bandwidth and processing power for... virtually little to no gain.
I am more interested in Colour Space, does it mean we get Rec 2020?
Also, frankly, the last thing I worry about every day is whether I can turn off anti-aliasing yet. Text has been comfortable on computer monitors for a long time now.
https://www.samsung.com/global/galaxy/galaxy-s8/specs/
> Galaxy S8 5.8" Quad HD+ Super AMOLED (2960x1440) 570 ppi
Rtings has close-up pictures of the layout of OLED screens. Those are TVs but I would think monitors are the same.
I think only phones sometimes use pentile, probably because of the pixel density needed to fit 4k on a phone-sized screen.