(Editors' note: This is a primer for people who are unfamiliar with screen technology. If you're already well-versed, you might be more interested in my colleague Eric Franklin's screen tests, like this one between the iPhone 4, Morotola Droid X, HTC Incredible, and the Samsung Epic 4G.)
I don't know anyone who doesn't want their smartphone screen crystal clear, with saturated colors leaping off the display. But unless you're a screen tech buff, it isn't always easy knowing the difference between premium screens with fancy names like LCD Plus, Super AMOLED Plus, and Retina Display--and how they really affect the viewing experience.
We editors often describe awesome screens as "brilliant," "eye-popping," "rich," "smooth," and "gorgeous." Meanwhile, screen techies (and sometimes marketers) use terms like "color gamut," "NTSC," "filter matrix," "sub-pixels," and "luminance."
I'm no display technologist, but like many of you, I wanted to know what makes one screen "better" than another, and by which measure. So I dug around online, spoke at length with a couple of display experts, and tracked down answers from Samsung, HTC, LG, and Apple (which wasn't very helpful.)
It turns out that what makes a screen shine is a complicated, and often proprietary, blend of resolution, brightness, and color reproduction, with some other angles thrown in. To make it easier to follow, and to keep from sounding like a text book, I'll use a handful of flagship phones as examples of what makes your killer screen so lethal to the run-of-the-mill displays.
What's in a name?
Apple, LG, Samsung, and Sony own the names for their screens and the technology that goes into them. It gets a bit confusing because proprietary names often mirror general terms. The "AMOLED" In Samsung's Super AMOLED Plus screen stands for "active-matrix organic light-emitting diode," but some of that is there for emphasis. Most of today's OLED screens already employ "active matrix," a common way of dealing with pixels on a liquid crystal display. The same goes for Super LCD, a brand name for Sony's specific makeup of a liquid crystal display. Then there are screen names that seem purposely vague. Apple's Retina display evokes human vision without revealing the technology behind it, and LG's Nova screen simply states that it's new.
iPhone 4: Resolution
Part of what makes the Apple iPhone 4 so "magical," at least to CEO Steve Jobs, is its high pixel density. Once you reach a certain number of pixels per inch (ppi), Apple says, the human eye can no longer detect the difference between them, which makes the image look perfectly smooth. If you believe Apple, the 326 pixels per inch (ppi) of its Retina display is pretty close to the magic number. Indeed, it looks nice and sharp.
To achieve this, the iPhone 4 features a 960x640-pixel resolution on a 3.5-inch screen. The Retina display's resolution is still the one to beat, but screen size is also key. For instance, the forthcoming Motorola Droid Bionic will feature a quarter-HD (qHD) 960x540-pixel resolution on a 4.3-inch screen. Although the Bionic's resolution approaches that of the iPhone 4, its (fewer) pixels will spread out on a notably larger screen, making the overall density smaller. There are other factors in addition to resolution and density that contribute to a sharp viewing experience, but the main point is that your eye will notice too few pixels on a too-large screen. For reference, DisplayMate.com includes pixel density as one factor in a detailed comparison chart.
