You might recall, if you watched the iPhone 4 keynote or followed it closely, that Steve made a certain claim about the new Retina display. I’ve seen a few posts around the net today disputing it and calling it false advertising, but really now.
Here’s what Steve said, word for word:
It turns out that there’s a magic number right around 300 pixels per inch that when you hold something around 10 or 12 inches from your eyes is the limit of the human retina to differentiate… and at 326 pixels per inch we are comfortably over that limit.
An expert has been consulted, who says that once we do the requisite optical conversions, at 12 inches the actual retinal resolving power would be something like 477 pixels per inch. Well, I have no doubt that in a way, he’s right. The retina (I’m assuming this is in the fovea) is an amazing visual machine, and I have no doubt that it would be able to discern individual pixels at 326ppi at 12 inches, if you presented it correctly.
For all intents and purposes, however, including advertising purposes, Jobs is well within reasonable limits. And do you think they just made up the numbers? Apple has physicists too! By the way, if you want to call me an Apple apologist, this is coming from a guy who mocked Apple for the actually misleading “Twice as fast, half the price” campaign. The fact is that this display is a huge improvement over all existing displays, and it exceeds the DPI used to print books and magazines. He may have overstated it as being the actual physical limit of the retina, but the practical meaning of that remark was that you won’t (without effort) be able to differentiate between a 300ppi display and a 400ppi display. On the other hand, you could instantly see the difference between 200dpi and 300dpi.
Anyway. It’s really a non-issue, since the display is the sharpest in the world and we’re complaining about how technically, physics allows for a sharper one. Let’s move on, if you please.
Update: Just noticed this little tidbit, though. Samsung says the display isn’t all that, and that its Super AMOLED displays are just better. The pixel density just isn’t there, though. As I noted on the day of, 800×480 in a 4″ display is significantly less impressive than 960×640 on a 3.5″ display. He says the improvement is only “3-5%,” but that sounds like a nonsense number to me. The improvement is substantial and observable. But I do agree that Super AMOLED is a superior base technology for displays. It’s just not as good as Apple’s IPS tech right now.
Update 2: response to commenters below. Also, Bad Astronomy agrees with me. Soneira was using somewhat unrealistic optic qualities in determining the “resolution” of the eye. It’s worth noting, too, that the “resolution” of the retina is pretty much a nonsense term, psychovisually speaking. The lens determines the resolving power (just like in cameras) and even then, the network of sub-sensors in the retina making up groups will confuse things further, and then of course the visual system performs transformations and optimizations to the raw data provided by the retina, so what you see is pretty far from the theoretical limits being disputed. Jobs probably should have said resolving power of the “eye,” not retina, though.