[esolyt]

What does retina mean? Can you explain to us?

Do we really need a term for "high PPI"? If iPhone 4 is retina, then what is Xperia S? It is certainly not retina, because it would be insulting to call it retina when its pixels are even more indistinguishable. What about Galaxy Nexus? It is 316 PPI, slightly less than iPhone. Is it enough for being retina or not? Who determines?

[potatolicious]

The original contention is that it is the absolute (useful) peak of screen resolution, as in, at the distance the screen is normally viewed from, the individual pixels are imperceptible to the human eye, and adding more will not result in any perceptible difference.

Similar to print media, where beyond a certain dpi your eyes just can't tell the difference if you added more dots.

[esolyt]

Your definition of retina is based on 2 assumptions:

1) Everyone has the same eyes.

2) Everyone holds their phone at the same distance.

Both of these assumptions are incorrect. Therefore, a display that is retina to you, may not be retina to me. It is therefore meaningless to talk about whether a display is retina or not (unless a specific human and a specific distance is specified).

[potatolicious]

Your argument is faulty, and here is why:

You are confusing with "these assumptions are not true 100% of the time" with "these assumptions are not true most of the time". In fact, just like sound perception, motion perception, and eyesight resolution, the vast, vast, vast majority of the world is tightly clustered around a maximum.

There are a small number of humans who can hear above 20kHz, but that doesn't change the fact that 99% of the world can't - in fact, most adults sit closer to 16Hz. Ditto, for the vast, vast majority of the people on this fair planet, framerates above somewhere between 70-80Hz become imperceptible, with a lot of people sitting closer to 60Hz.

Both audio and video equipment are engineered with these limits in mind, and there is no fundamental problem with engineering screens with the limitations of the ultramajority in mind.

The fact that there are a few extraordinary individuals whose sensory abilities far exceed that of the rest of the population, does not make it "meaningless" as a concept. What is "retina" as defined above, is retina to everyone but the statistical outliers.

To address your original post, it seems like you're taking out your Apple rage against a concept that is older than Apple. "Retina" as Apple uses in its own advertising is really whatever the damn hell Apple feels like calling retina, but the concept predates Apple's usage of it and has validity. The Xperia S, the Galaxy Nexus, are all "retina" in the non-Apple-marketing sense of the word.

[tejaswiy]

For me, after a threshold (which is what the iPhone display reaches), it doesn't really matter. The returns are exponentially diminishing after that point. Having 10% ppi more than the iPhone's will not make the display 10% better.

[Johngibb]

How can pixels be "more" indistinguishable? Either you can see them or you can't...

[jarek]

You see them or you don't at a given distance. There might be value for some people in having that distance be shorter.