A Retina Display With 44%-Greater Color Saturation? Whoa.
We spend a lot of time talking to marketing folks, many of whom are great, great people. But it's their job to sell you something, and it's our job to figure out if their claims are true or not.
When Apple introduced its Retina Display on the third-gen iPad, the company made a big deal about improved color fidelity and sharpness. In fact, the screen's name came about due to pixel density so high that the human eye is purportedly unable to discern the individual elements that compose an LCD screen.
The iPhone 5 enjoys even higher pixel density than the third- and fourth-gen iPads, but this is actually necessary to compensate for a shorter typical viewing distance. That is to say you're expected to hold an iPhone closer to your face than an iPad. But the iPhone 5's pixel density isn't any better than the iPhone 4S, or even iPhone 4. They both offered 326 pixels per inch as well, translating to 57 pixels per degree of view angle (53 is Apple's cut-off for applying its Retina Display marketing).
Apple does claim, however, that the iPhone 5 enjoys 44% more color saturation than its predecessor. This means that the dominance of each hue in a given color should be stronger, and we can indeed concur that colors appear more intense on the latest iPhone iteration.
The iPhone 4/4S had a good display, but a side-by-side comparison between those earlier models and the iPhone 5 makes it easier to subjectively favor the iPhone 5 (don't worry, the next page is full of more scientific data).
It's difficult to put the iPhone 4S and iPhone 5 under a microscope and, using the same settings, create a side-by-side comparison. The iPhone 5's pixels are closer to the surface of the glass than before, resulting in the following shot:
We can unzoom just a bit and get a clearer view of the iPhone 5's subpixels.
The touch sensor is now integrated into the iPhone 5's display, whereas it was previously underneath the cover glass on past models. This is a contributing factor to why Apple's iPhone 5 is thinner than its predecessor.