Why high resolution screens matter for Apple's iPad 2
When displays go Retina
If iPad 2 has no reason to dramatically increase its pixel density just for HD video playback, and is not designed to expand its apparent desktop size as PCs historically have, what good is a fantastically high resolution?
The answer is apparent in iPhone 4, which leapfrogged other smartphone-sized devices in terms of display quality while being completely compatible with all existing iOS software, unlike the Galaxy Tab.
Other Android smartphones have increased both their resolution (although not as much) and their physical screen size (which actually decreases the pixel density at the same resolution, making the display look slightly more pixelated).
While some users prefer a bigger phone, the Retina Display of the iPhone is more than a specification bump; it pushes the display from looking like a computer screen into being photorealistic on the level of very high quality print magazines.
A similar Retina Display on iPad 2 would propel Apple well ahead of competitors who are just now preparing to launch Android 3.0 tablets with larger than 7 inch screens, similar to how iPhone 4 shut down the lead Android smartphones had threatened to take early last year.
While part of iPhone 4's disruption of the Android deployment at Verizon was clearly related to iOS 4's shattering of previous limitations that Android didn't have, including multitasking features such as background audio playback, it was the hardware of iPhone 4 that got the most attention in product reviews, ranging from its industry leading HD video and still rear camera to its front facing FaceTime camera to its solid construction and, of course, its spectacular screen.
Rather than wondering what users might do with a high resolution iPad, it's useful to note what Apple might not do were it not to draw marked distinction between its iPad and the coming contenders from HP, RIM, and the Android licensees. It appears that Apple may not be able to extend its lead without dropping a bombshell on the nascent tablet business.
Skating to where the puck will be, but staying on the rink
Instead of attempting to maintain parity with competitors, Apple needs to anticipate practical, valuable features before customers (and competitors) even realize they exist. The SGX543 graphics processing cores that iPad 2 is expected to use have existed since 2009, but they haven't been put into use because the components needed to deliver an iPad Retina Display resolution haven't been affordable.
Apple's economies of scale, currently being driven by millions of iPad sales, could enable the company to bet on the new technology and roll it out well before it is cost effective for other makers. Apple was already ahead of other manufacturers in being able to deliver a full sized 9.7 inch tablet starting at $499, but it could only do that by banking on being able to sell millions of iPads in its first year.
That, in turn, was only possible if Apple invested lots of time and effort into making the iPad platform attractive to existing iOS developers. By making iOS apps relatively easy to optimize for iPad while retaining a familiarity in ease of use for existing iOS users, Apple fostered the growth of a huge library of iPad-specific apps, something that hasn't occurred for Android tablets.
In contrast, Google is preparing Android 3.0 Honeycomb (as presented below) to exclusively serve a new crop of tablets with an entirely new 3D user interface that offers little familiarity to existing Android smartphone users.
RIM is similarly preparing a completely new operating system to power its 7 inch PlayBook tablet, which offers little in common with its BlackBerry OS 6 smartphones.
Other makers, such as Asus, are planning to use Windows 7 to hit the high end of the tablet market while using the mutually incompatible Android to target enhanced netbooks with more limited features.
Leveraging resolution independence
Apple faces certain issues in further increasing the resolution of its desktop and notebook Macs. If it doubled the resolution of its MacBook line, for example, window controls and the menu bar would become nearly invisible. The company has been developing resolution independence into Mac OS X, but this requires existing third party apps to draw everything on the screen in a way the operating system can scale to the preference of the user.
Mac OS X icons and the Dock have always scaled smoothly, and since Mac OS X Tiger there has been a hidden option to scale up window controls and menu bars to cope with increasingly higher screen resolutions. However, third party Mac apps may be created in Carbon, Java, Flash, or some other custom API that doesn't scale consistanly, resulting in unsightly jaggies or misplaced screen elements that look bad. The overall display of text needs to be scaled as well, to prevent characters from shrinking into microprint as the resolution grid packs more and more pixels into the screen.
The payoff for increasingly higher desktop screen resolutions is also limited. Users are already facing content overload as they peer into the display resolution of a 30 inch Cinema Display. Mobile devices are slightly different however. The iPad's existing pixel density is 132ppi, compared to iMacs hovering around 100ppi and MacBooks ranging from 110 to 135ppi (on the new 11 inch MacBook Air). At reading distance, the iPad's pixels are discernible; most people position their notebooks significantly further away, making individual pixels less obvious.
Prior to iPhone 4 (boasting 326ppi), Apple's highest screen density appeared on iPod nano models, ranging from 200 to 260ppi. In contrast, a 42 inch 720p HDTV offers just 35ppi, while a 60 inch 1080p set delivers 37ppi. The value of pixel density, clearly, relates to how close you're viewing a display. High resolution is actually rather unnecessary for impressive HD video when viewed across the living room, but is essential to deliver a sharp display on a mobile device held at the reading distance of a book.
Having already created a user interface that works well on a 9.7 inch display, Apple is now free to dramatically boost the iPad's resolution independently of its screen size, in order to deliver a very realistic depiction of photos, ebooks, documents, videos, and dynamic content that users navigate via touch while holding the display at distance where pixel density is readily noticeable.
So rather than needing super high resolution video content, the expected iPad 2 can present existing iPad apps (ranging from Netfllix to NPR) at full fidelity while allowing optimized apps to draw images, text and other content with razor sharp detail at a pixel density where individual dots begin to vanish from view, exactly like iPhone 4.
And because Apple has designed the iPad user interface from the ground up to be resolution independent, doubling the resolution doesn't have the same drawbacks involved with boosting pixel density on desktop or notebook systems. With a resolution nearing the retina's detail threshold, iPad 2 can deliver a user interface capable of exceptional quality, without demanding higher quality video sources than currently exist.
At the same time, photographers and anyone else who deals with detailed images, ranging from X-rays and MRI images to detailed PDF renderings and 3D architectural models, will benefit from the resolution boost because it will simply be there to use. Even users with basic needs for iWork productivity apps, browsing the web, and playing puzzle games will benefit from razor sharp rendering of text (that iOS is capable of doing automatically) and enhancements third party developers make to their custom graphic assets (which are easy to add to existing apps).
The resolution independent design of iOS will also allow Apple to potentially sell both new iPad 2 models with a very high resolution as well as the existing iPad at a low price tier, without causing fragmentation issues for developers or users. The same apps can run seamlessly on both, supplying normal or double resolution graphic assets as needed to take full advantage of the new screens while still working normally on existing models.
Of course, Apple hasn't yet revealed its hand on iPad 2 yet. But if 2011 follows the developments of 2010, as internal and external evidence suggests it will, it shouldn't come as a surprise to see Apple flexing its resolution independent muscle to differentiate its tablet offerings.