So I've been comparing my ipad3 to my ipad1 (I didn't get an ipad2 because I only wanted the higher density screen)

Back in 1999 I saw a technology demonstrator at IBM's Almaden facility in San Jose where they showed a 200 ppi LCD display. It blew me away. The scientist who worked on it talked about eye strain and how 200 ppi was the 'magic' spot where more thank 75% of the people stopped noticing the strain of making lines out of pixels.

So after unpacking my ipad3 one of the first things I did was to download the Economist app (my favorite btw) and bring up the latest issue on both the ipad1 and ipad3. Side by side the difference is very visible, absolutely can distinguish between the ipad1 and 3 with p < 0.01 :-) More interestingly comparing the ipad3 version to the print magazine its clear that the ipad3 is pretty much identical from my eyes perspective (disclaimer I do wear glasses, no 20/10 vision here).

Now if I could convince folks that send me catalogs to offer an ipad version I'll be in good shape.

There's a big spread to visual accuity. There are two big factors: receptor density on the retina and near-field focus ability. The former doesn't vary too much I'm told, but the latter can be 3-4x better in some people than others. I can focus reliably on a high contrast object at about 6" or so. Some people can apparently do it at 3-4". And of course it gets worse as we age. Far sighted adults have trouble reading at arms length, even.

I can certainly believe that. I'm a long way from perfect sighted, but I am apparently close to the average once corrected. The fact remains though that the pixel density is comparable to phones released a couple of years ago, and the distance between 'retina' and 'non-retina' is mere inches.

It is the old audiophile argument I guess, we'll never know for sure without double blind testing. I would like to give that a trial, sit people at 10" from a black mask screen with a small rectangle in it, display a pure white image at the lowest brightness and see what people report.

Gizmodo just made a simple blind test. Not a fully controlled double blind test, but still interesting:

http://gizmodo.com/5894094/we-people-an-ipad-2-told-them-it-...