Now: 300ppi is the most you need to completely fool the eye (similar to how 24fps is typically considered all you need for fluid motion)
Then: Given 2004's technology, 100ppi is the best compromise between a tiny unreadable display with high ppi and a large pixelated display with low ppi
If one uses 300ppi @ 11inches as the standard for a "retinal" display, 100ppi becomes retinal at 33 inches. I don't sit quite that far from my screen, though I suppose some people may.
And a couple other popular smartphones have been retinal at their typical usage distances for several months now.
Apparently 20/20 vision is defined as being able to distinguish things 1 arc-minute apart. This comes to 114 dpi at the 30 inches away that I just measured my screen at. And yet when I pick a small-but-generally-readable font, I can see that for example the leftmost leg of an 'm' looks different than the other two.
So I would say you want sufficiently high resolution that pixelization artifacts aren't visible, which means that adding or subtracting one pixel from a one-arc-minute item leaves it still at one-arc-minute. Maybe 2px/arc-minute would do this well enough, maybe it would take 3. But 1px/arc-minute still permits visible artifacts.
I need a diagram. I'll use the one on wikipedia's visual angle page.
At 11 inches, 1 inch has a visual angle of about 5.2 degrees. But the exact number doesn't much matter. You can set two instances of the visual angle equation equal (one for the unknown distance and one for the definition of retinal, an inch long at 11 inches distance), and simplify to give you what similar triangle ratios would too. A length, s=D/11, for the side of the similar triangle opposite the eye, which by the operating definition of "retinal" has 300pixels along it. So, we can use s as a scaling factor, 300ppi/(D/11)="ppi you need at distance D to be retinal". Solve for D instead if you wish.
That might not even be clear with the diagram, sorry.
24fps is not "the most you need to completely fool the eye." There's a reason gamers want high fps; because humans can definitely perceive the difference.
24fps is what's needed for film, because it's fast enough for persistence of vision to carry one frame's image over to the next while the shutter is closed. And in film, motion usually gets smoothed by the non-zero exposure time. If video games could employ sophisticated motion blur, they could generally get by with 24fps as well.
24fps is not based on persistence of vision. Persistence of vision exists at 23fps or 22fps and lower for some people. 24fps is an historical artifact of the first few generations of motion picture technology. It is maintained because humanity has grown accustomed to 24fps in theaters for film material. With the advent of video (video tape) and prolific 30fps material (60i material), many people perceive film shot at 30fps to be video and vice versa.
24 fps is barely acceptable. Forget fast pans and any other fast camera movement. Increasing that number will be hard, though, because over decades we learned to associate 24 fps with cinematic quality and higher frame rates with cheapo camcorders.
Not really. Actually I think the GP was mistaken. The big reason gamers don't want 24FPS is because if it's 24FPS during normal play, it's gonna stutter. There will be times when it goes down to, say, 12 FPS, if not lower. And 12 FPS is simply not good enough for anything.
And of course, there's one thing about employing sophisticated motion blur-- you're not going to do it just to lower FPS. Real motion blur is quite expensive. There's really no point except for the visual coolness.
A lot of my film buff friends claim that films with higher than 24 fps look a lot better. There's a kind of format called Maxivision that can be projected 48:
Let us consider the claims being made.
Now: 300ppi is the most you need to completely fool the eye (similar to how 24fps is typically considered all you need for fluid motion)
Then: Given 2004's technology, 100ppi is the best compromise between a tiny unreadable display with high ppi and a large pixelated display with low ppi