iPhone 4's retina display claim put under the math microscope

Samsung might have entertained us with some trash talk about the iPhone 4's IPS LCD yesterday, but this stuff is of a rather more somber variety. Raymond Soneira, president of monitor diagnostics firm DisplayMate, has said that Apple's retina display marketing is inaccurate, because he believes a display that truly makes pixels indistinguishable to the human eye would require a density in the vicinity of 477dpi. The iPhone 4 has 326dpi, and by now you might be surmising that Steve Jobs flat out lied when he said that the iPhone 4's pixels are too small for the human retina to discern from 12 inches away.

But not so fast, says Phil Plait from Discover, whose résumé includes calibrating a camera on board the Hubble space telescope. He's done the math too and finds that the 477 number applies only to people with perfect vision. For the vast majority of us, Steve's claim stands up to scrutiny; even folks with 20/20 eyesight wouldn't be able to tell where one pixel ends and another begins. So it turns out Apple can do its math, even if its marketing isn't true for every single humanoid on the planet.