Quote:
Originally Posted by scottjl
true, but are all those extra dots actually distinguishable by the human eye? what jobs is basically saying is that a 1' distance (where you'd likely hold the phone) the new screen has the finest resolution the human eye (and I'm guessing he means average person) can distinguish. maybe we need an opthamologist to chime in here.
|
Ok, first of all you need to divide the dpi value by 2 to get the top limit of the spatial frequencies that the device can render, so 326ppi gets you 163lpi (lines-per-inch, a measure of the spatial frequency of optical features).
163lpi gives a feature size of 0.00614", or 0.156mm. A 0.156mm feature 1' (or 304.8mm) away subtends an angle of 0.0293 degrees, or 10.5arcseconds, which certainly exceeds all estimates of visual acuity (which probably tops out at 24arcseconds).
See also
Waite and Oliver, 2006, which gives experimental evidence that 150lpi is satisfactory for the majority of viewers.
So, Jobs is right on this, there's no point boosting resolution further. What's needed is to produce this kind of resolution on a screen bigger than 3" (cough, 66lpi iPad, cough).
[Edit]Oh, and when talking about the dpi of offset press you need to take into account their use of a halftone screen, which another why it's best to think in terms of lpi instead.