Pixel Doubling: Why it Works on iOS, Why it Won’t on OS X

Apple doubled the horizontal and vertical pixels from 480×320 in the iPhone 3GS to 960×640 in the iPhone 4. This worked because there was a single 3.5-inch display with 480×320 in landscape. From a manufacturing point of view doubling the pixels on a small 3.5-inch LCD was difficult but not impossible. Pixel doubling won’t work for OS X precisely because there is more than one display on the Mac side, probably impossible to volume manufacture at affordable costs with current technologies, and more than what Apple is trying to achieve.

In The Resolution Gap I focused on MacBooks and listed their respective resolution, or pixel density:

  • 11.6-inch 1366×768: 135 ppi
  • 13.3-inch 1280×800: 113 ppi
  • 13.3-inch 1440×900: 125 ppi
  • 15.4-inch 1440×900: 108 ppi
  • 15.4-inch 1680×1050: 129 ppi
  • 17.0-inch 1920×1200: 133 ppi

I also noted that the 13.3-inch 1280×800 and 15.4-inch 1440×900 would be dropped from the lineup in the near future, leaving the MacBook line with four different display sizes, pixel formats, and resolutions. What I am most interested in is resolution, which determines the visual experience of OS X.

The range in resolution is smaller than I first thought: 125 to 135 ppi. Apple has done two things in terms of resolution. First, the company has continued to shift to displays with higher ppi, from around 100 in the early 2000s to 110 a few years ago to an average of about 130 today. The difference in the visual experience among the four higher-resolution MacBooks is quite small, which is a good thing since Apple wants a more unified, controlled, perfected experience for users. For the sake of argument, let’s quantify the difference in visual experience by taking the difference between the lowest ppi (125) and the highest ppi (135). The 125-ppi user will experience a difference of up to 8% and the 135-ppi user 7.4%.

What would happen if you pixel doubled these displays?

First, let’s talk about why Apple might want to pixel double. Pixel doubling is logically simple. The current 15.4-inch 1440×900 MacBook Pro pixel doubled is 2880×1800. All the UI elements remain the same size but clarity is quadrupled. The math is nice and clean. But, this is impractical for a couple of reasons.

Apple has stopped bringing to market products that are too innovative. I give you the Newton as a good example. The Newton, introduced in 1987, was a technological masterpiece, but was too early, by around 10 years. If the Newton had been introduced after Palm kickstarted the PDA craze it would have garnered much more attention and probably some success. Apple was literally a decade ahead of the competition, but also too far ahead everything else. A ubiquitous and affordable cellular infrastructure wasn’t there. Mobile computing was just getting started and the majority of people didn’t yet have a need for or realized they needed a PDA. There were many other reasons for its failure, including a sky-high price, but the main reason for Newton’s failure was that Apple was too early.

Today’s Apple isn’t like that. Apple brings about products that are revolutionary but not only in terms of technology. The iPad is revolutionary because there was nothing like it before, because anyone could use it, and because it was affordable, something the Newton never was. Apple focuses on the complete user experience and makes sure that its products, especially the iPhone, iPod touch, and iPad, are eminently usable both physically and visually. Pixel doubling on OS X is like the Newton: way too much for what we need and want today. That’s one reason why I don’t think Apple will pixel double its MacBook line.

Another reason is to figure out what Apple is trying to achieve. What is Apple trying to get at? A visual experience I’ll simply call the Retina Experience where your eyes cannot decipher individual pixels. The icons, text, and graphics will look seamless. Apple will craft its Retina Experience on its MacBooks based on a thorough understanding of our visual system and how we use our MacBooks.

In The Resolution Gap I proposed that the distance between our eyes and the display on a MacBook was 18 to 20 inches. I base my assumption on what Steve Jobs said about the usage distance of the iPhone, which was stated as 12 inches. The iPad is probably around 15 to 18 inches. The MacBooks a bit farther back at about 18-20 inches. At that range here is the list of pixel formats and resolutions to achieve a Retina Experience:

  • 11.6-inch 1920×1080: 190 ppi, 18.1 inches
  • 13.3-inch 2160×1350: 192 ppi, 18.0 inches
  • 15.4-inch 2400×1500: 184 ppi, 18.7 inches
  • 17.0-inch 2560×1600: 177 ppi, 19.4 inches

In my opinion, these displays are manufacturable today using technologies. Compared to pixel doubling these pixel formats are conservative. For three reasons:

One, these pixel formats based on how we use our MacBooks meet Apple’s definition of a Retina Display. Second, Apple is sensitive to our willingness to pay for its products. The pixel doubled displays would be too far out there and prohibitively expensive. Third, a pixel doubled line of MacBooks wouldn’t work toward unifying the visual experience. The disparity in the visual experience of OS X on MacBooks will remain the same. At the Retina level the disparity disappears since we are no longer able to visually see the differences.

To conclude, pixel doubling displays used in today’s MacBooks will be too far ahead of the game, too costly, and beyond what Apple is trying to achieve. Instead Apple will bring us a Retina Experience where visual differences among MacBooks will disappear. There is little gain in moving beyond the point where visual differences evaporate. I’ve focused on MacBooks, but Apple with Retina Displays across its entire line of products will bring us an experience of using OS X that is unified and near visual perfection.