The advent of last year's iPhone 4 caused quite a stir with its high resolution Retina Display. So, when the iPad 2 was announced, we were expecting to see that Apple's next-generation tablet would follow suit with a Retina Display of its own. It didn't, but that doesn't mean that it falls short when compared to its smaller iOS brother. Whether we're watching a movie, playing a game or browsing the web, the iPad 2's display really does impress, and as Dr. Raymond Soneira, President of DisplayMate Technologies points out in his recent iPad and iPhone display shoot out, the two iOS devices are like two peas in a pod -- or, as he puts it, Arnold Schwarzneggar and Danny DeVito's characters in Twins.
"I was surprised and shocked that the iPad 2 tested identical to the iPhone 4," Dr. Soneira says of his latest study, where he pitted three iOS devices -- the iPhone 3GS, the iPhone 4 and the iPad 2 -- against each other to compare their displays. "Apple put in a very high quality IPS LCD into that iPad -- it's an outstanding display." A detailed comparison table on Dr. Soneira's study (seen below) shows that the iPad 2 has almost identical performance to the iPhone 4's Retina Display. But where the difference is noticeable is in the iPad 2's larger display, which makes the lower Pixels Per Inch (PPI) more apparent. "It would be really nice to get that PPI higher," says Dr. Soneira, but adds that Apple will inevitably do something about that in a future iteration of the tablet device.
Because they're both so similiar, the iPad 2 and iPhone 4 also come with the same share of inadequacies. For starters, one of the bigger setbacks -- a problem that actually plagues most smartphones on the market today -- is their faulty automatic brightness controls. Most smartphones and tablets are supposed to adjust automatically based on a sensor that detects the amount of light in the room you're in, but because most sensors stare right at the user, it's not actually capturing ambience. So, instead of adjusting properly, the iPad 2 and iPhone 4 are both wasting precious battery life if the user doesn't adjust the screen brightness themselves -- an inconvenience when one has to navigate several screens to get to this option.
Another major issue with both devices is that their range of color gamut is too small. Color gamut is the range of colors that the display can produce; it's so much less than what the human eye can see (as illustrated by the diagram below). What Apple has done is made its red and blue primary colors a little on the weak side, which sort of distorts the color of images, though it's not really noticeable unless you're, say, looking at photo of an object or person you're very familiar with in real life.
The iPad 2 also has an issue with anti-aliasing, which is supposed to make images appear less pixelated and easier to read. "I was a little bit bothered when I noticed the anti-aliasing on the iPad 2," says Dr. Soneira. The lower PPI of the iPad's resolution means that it needs better anti-aliasing than the iPhone 4 to make up for that added space. He adds that you really only notice it with smaller texts, but that in comparison to some netbooks on the market, like an Asus 1201N, it could do better.
Fortunately, all it takes to essentially perfect the displays of the iPad 2 and iPhone 4 are a couple of software updates. Dr. Soneira uses anti-aliasing and notebooks as a good example because of Microsoft's implementation of ClearType, a sub-pixel rendering technology that makes the typeface crisp, clear and easy to read, no matter the display. If Apple were to do the same in a future iOS update for the iPad 2, it could help exponentially with text rendering.
The same could be done with the brightness sensor, too. And for color gamut, Dr. Soneira says that changing the backlighting could help improve this on both iOS devices. "Color gamut is [the device's] weak point and there's a way to tweak that a bit to get more color and not eat up lots of battery power." Changing the backlighting in both the phone and tablet would also help.
But even if a major software update does happen to remedy these display follies, will the iPad 2 ever join the iPhone 4 in sporting a Retina Display? Dr. Soneira thinks it doesn't make too much sense. "It would take four times as many electronics, processing and [battery] power" for a Retina Display, he says. "There are big penalties in terms of price and in terms of power that make it not an optimum logical choice."
Dr. Soneira plans on releasing another study next week about what the manufacturers can do to optimize mobile displays. The study will cover ways to increase the LCD color gamut, examine IPS LCD (iPhone 4) versus OLED (many Android phones), power efficiency, ambient light sensors and more. If you want to read more about this study in-depth, check it out on the official DisplayMate page.
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