Why You Might Be Disappointed By The Resolution Of Those New Retina Display Macs [Feature]

Why You Might Be Disappointed By The Resolution Of Those New Retina Display Macs [Feature]

How many does pixels does a Mac really need to qualify as Retina, anyway?

It’s looking increasingly likely that when Tim Cook takes the stage at the annual WWDC keynote on June 11th, Apple will announce new MacBook Pros and possibly iMacs, and if the rumor mill is to be believed, these new machines won’t just be slimmer and ditch their optical drives… they’ll be the first Macs with Retina displays.

What everyone widely expects from Retina display Macs is an iPhone or iPad-style resolution doubling. So if the current 15-inch MacBook Pro has a 1,440 x 900 display, the Retina 15-inch MBP would have a 2,880 x 1800 display.

What the rumor mill is missing is that there’s no benefit to Apple handling a jump to Retina display Macs this way. The reason the iPad and iPhone going Retina was such a big deal was because they had really pixellated displays. Before the iPhone 4, the iPhone had a display that was only 53% close to being Retina. The iPad was slightly better, at 61%. Roughly, both the iPad and iPhone were only about halfway there, which made the easiest fix to just double the amount of pixels per inch.

But Apple doesn’t need to do this with its line of Macs. In fact, it’s likely that most “Retina Quality” Macs will have fewer pixels than your new iPad. Here’s why.

Macs Are Already Almost Retina Quality
Why You Might Be Disappointed By The Resolution Of Those New Retina Display Macs [Feature]

You might not know it, but this iMac is already 89% a Retina display.

When we talk about an iPad or iPhone having a Retina display, what we’re talking about is that the pixels on that display are so densely packed and so tiny that they are not discernible to the eye of a person with 20/20 vision. Nothing looks pixelated. We measure the sweet spot for how densely packed a display needs to be to qualify as Retina in pixels per inch.

There is no magical number of pixels per inch that automatically equates to Retina quality.

Simple so far, right? Here’s the thing, though: there is no magical number of pixels per inch that automatically equates to Retina quality. The iPhone 4S achieves Retina quality at 329.7 pixels per inch, while the new iPad only needs 214.9 pixels per inch to qualify as Retina. Why? Because you hold your iPad further away from your eyes than you hold your iPhone. That means the iPad doesn’t need as many pixels as the iPhone to seem crisp.

The closer a display is, the smaller and more densely packed the pixels need to be for your eyes not to be able to resolve them. The farther away a display is, the larger and more loosely packed the pixels can be. What all this means if you sit farther back from your Mac than you do your iPad — and everyone does — it doesn’t need as high a resolution to qualify as a Retina display.

There’s a formula for determining how many pixels per inch a display needs to be to achieve “Retina” quality, as provided by Dr. Raymon Soneira of DisplayMate Technologies. Using this formula, it’s pretty easy to tell how many pixels per inch a display needs to qualify as Retina. And helpfully, TUAW’s Richard Gaywood has always done the math.

Here’s how close they are right now:

ModelScreen Size (Inches)ResolutionAverage viewing distancePPI for “Retina”Closeness to Retina
11-inch MacBook Air11.61366 x 76822156.387%
13-Inch MacBook Air13.31440 x 90022156.382%
15-Inch MacBook Pro15.41440 x 90024143.277%
15-Inch MacBook Pro (High Res)15.41680 x 105024143.290%
21-Inch iMac21.51920 x 108028122.883%
27-Inch iMac272560 x 144028122.889%

As you can see, the Mac farthest away from qualifying as Retina is the 15-inch low res MacBook Pro, which is 77%, while the high-res 15-inch MacBook Pro is 90% a Retina display. Almost every other Mac hovers around 80-90%.

See what we’re getting at here? Apple doesn’t need to start doubling the PPI to achieve Retina. Across the board, resolution doubling is overkill. For the most part, every Mac only needs to bump itself up just a little bit. And using the above data and the Pythagorean theorem, it’s pretty easy to figure out exactly what the minimum real world resolution each display would need to be to be Retina.

ModelScreen Size (Inches)New ResolutionPPI For RetinaNew PPICloseness to Retina
11-inch MacBook Air11.61680 x 1050156.3170.78109%
13-Inch MacBook Air13.31920 x 1200156.3170.23110%
15-Inch MacBook Pro15.41920 x 1200143.2147.0102%
21-Inch iMac21.52560 x 1440122.8136.61110%
27-Inch iMac273840 x 2160122.8163133%

See? Not nearly so drastic. And actually, a lot of these minor resolution bumps are actually more “Retina” than the iPhone 4S, which only rates a 105% closeness to Retina, and the new iMac would “out-Retina” the new iPad, which has a 123% closeness to Retina. These resolutions would be just fine.

Besides, there’s there’s another problem with PPI doubling…

Battery Life
Why You Might Be Disappointed By The Resolution Of Those New Retina Display Macs [Feature]

Due to the demands of the Retina display, the new iPad is almost all battery.

The demands a Retina display makes on a Mac’s battery isn’t a problem for the iMac, of course, but it’s a huge issue for the MacBook Pro and MacBook Air.

Let’s look at what happened with the new iPad. When Apple introduced a Retina display to the iPad, they had to increase the battery capacity from 6,944 mAH to 11,666 mAH, an almost 70% bump. The result was a thicker, heavier iPad that took significantly longer than the previous generation to charge.

The display is the most power hungry element of almost any device. More pixels = more battery drain

Why was Apple forced to stuff so much more battery inside the new iPad just for a Retina display? It’s complicated, but the simple answer is that your display is the most power hungry part of almost any device, and if you increase the pixels, you increase the amount of electricity it needs to draw. The more advanced answer is that for LCD displays, the transistors and circuitry that actually connect the pixels together behind the pixels become a far denser web when you increase pixel density, and therefore the device has to output much more light to shine through. Either way, more pixels = more battery drain.

Apple likes to keep their devices as thin and light as possible, and batteries are one of the heaviest and thickest elements of any device. Keeping this all in mind, why would Apple possibly undertake the huge battery hit of a PPI-doubled HiDPI display in the MacBook line when they could simply bump the resolution of each model up by one level each and still be able to accurately describe them as new Retina MacBooks without taking such a hit in power management?

Resolution Independence
Why You Might Be Disappointed By The Resolution Of Those New Retina Display Macs [Feature]

OS X is already great at managing all sorts of resolutions.

So far, we’ve shown that Apple doesn’t have to increase the pixel density of the current MacBook and iMac displays by that much for them to qualify as Retina, and that taking this more modest approach will actually save battery life.

There’s another reason though why Apple doesn’t have to double the pixel density of Mac displays if it wants to go Retina: OS X is much, much more resolution independent than iOS is.

Why You Might Be Disappointed By The Resolution Of Those New Retina Display Macs [Feature]

Resolution independence at work. Note the pixellated Apple logo.

Resolution independence is when elements of a computer screen are rendered at sizes independent from the pixel grid. In other words, instead of rendering an on-screen element — say, the Apple logo — by how many pixels it takes up, with each pixel in the file taking up exactly one pixel on screen, you magnify it according to how big it is meant to appear on the screen, using as many pixels as required.

What resolution independence does is allow you to display UI elements on a wide variety of display types and have them all look roughly the same size, whether that display is a MacBook Air’s 11-inch 1366 x 768 display, or a massive 27-inch Thunderbolt Display’s 2560 x 1440. And it’s a key part of OS X, a desktop operating system built from the ground up to support many, many different sizes of displays, with many, many different pixel densities.

That’s a lot different than iOS, an operating system that was built to only support two different display sizes: 3.5-inches (iPhone) and 9.7-inches (iPad). iOS is not resolution independent at all. In fact, the exact opposite is true: it’s quite resolution dependent indeed.

So when it came time to give the iPhone and iPad Retina displays, the easiest way for Apple to do it and maintain backwards compatibility with apps that didn’t have Retina support was to simply double the pixel density. In other words, if an onscreen element was only one pixel wide and one pixel tall on the iPhone 3Gs or iPad 2, display it as two pixels wide and two pixels tall on the new iPad. That’s effectively four times as many pixels!

But Apple doesn’t have to do this with OS X. The operating system and all of its apps can already handle numerous display sizes, resolutions and pixel densities just fine. There’s no benefit on the desktop side of things for Apple to simply double PPI across the Mac line across the board. Backwards compatibility will be just fine without.

Conclusion

Why You Might Be Disappointed By The Resolution Of Those New Retina Display Macs [Feature]

It’s possible that when Apple takes the stage at WWDC, they’ll blow everyone away with a new 15-inch MacBook Pros rocking true resolution doubled displays, but it doesn’t actually make a lot of sense. The higher PPI, the worse battery life becomes, and the Mac line doesn’t need an iPhone or iPad-style evolutionary leap when it comes to the mere resolution of their displays.

Apple already makes some of the best displays on the planet, and even when they go Retina, Apple won’t have to do more than give them a nudge. Besides, resolution’s only important as far as your eye can discern the pixels: once they are invisible to the eye, who cares? There’s more important things ultimately to the quality of a display — brightness, colors, darks — than mere resolution. Maybe once we stop racing to Retina, we can focus on them.

Related
  • InternDom

    outstanding points. I completely agree.

  • Rob Stevens

    The only thing that doesn’t make sense in all this is the quadruple-sized UI elements showing up in Lion and Mountain Lion. You can already switch on HI-DPI mode in Lion and see what happens when it assumes your display is “Retina” … on a 1920×1080 screen it renders the UI as if it were a high pixel density 960×540 display. There is no reason to assume that this isn’t what Apple is going to do … basically allow you to switch on a HI-DPI mode (or set it like that by default) on any display over a certain threshold. And considering that you have the equivalent of a 960×540 display at 1920×1080, the screens will HAVE to be larger than that. Your arguments were well reasoned, but ignored this basic fact … support for quadruple resolution screens is already in OS X, and existing screens are simply too small to accomodate.

    The battery life is a non-issue, for exactly the reason you claimed it was a problem … Apple squeezed a 70% larger battery into the iPad, and the differences were marginal: slightly thicker and heavier. You only notice the difference on direct comparison. Given that the Macbooks will have a little more room to play with, Apple can increase the battery life and probably shrink the devices, and still quote the same battery life numbers as today.
    When it comes right down to it, your article is too obsessed with what qualifies as a “retina” display, and ignores all of the details that we already know. There is no reason to assume that Apple will not be shipping out displays at least as high-res as what’s in the iPad, because Apple has already demonstrated that they are capable of doing exactly that.
  • mattbaty

    I agree.

    Oh, “How many does pixels does a Mac really need to qualify as Retina, anyway?”
  • John Brownlee

    The only thing that doesn’t make sense in all this is the quadruple-sized UI elements showing up in Lion and Mountain Lion.

    When it comes right down to it, your article is too obsessed with what qualifies as a “retina” display, and ignores all of the details that we already know. There is no reason to assume that Apple will not be shipping out displays at least as high-res as what’s in the iPad, because Apple has already demonstrated that they are capable of doing exactly that.

    Quadruple-sized UI elements is future proofing, not what’s needed, as stated above. As for whether or not Apple will be shipping out displays at least as high-res as what’s in the iPad, Apple’s in it to make a profit. There’s absolutely no need to ship displays that high resolution, and Apple can save money by NOT doing so, and getting by with more affordable, battery efficient and practical displays, as listed above.

  • jjustinschultz

    yes, please no spec for spec sake silliness. i’d like to save my gpu for pro apps.

  • ApplePr0n

    I mean, any resolution will be better than what it has, so it’s no big deal to me as long as it looks better than the current ones

  • ValSalva

    Text is still smudgy even at typical desktop and laptop distances.  Apple would not be working on double resolution assets if they were not serious about significantly increasing screen resolution.  

    The only downside is that graphics designed for non-retina computer viewing will look poor for a while.  Non-Apple apps may also look bad until updated.  App downloads will also get bigger.
    I just hope Apple eventually offers a 1680 X 1050 high resolution equivalent screen (3360 X 2100) for the 15″ MBP line.
  • xMoonDevilx

    And you think they are too stupid to already know this…..to making the resolution fit the display size, so as to be retina quality? No wonder you’re just a critic, and not on an Apple payroll.

  • aepxc

    The new icons in 10.7.4 are 1024×1024 px. So whatever the resolution bump on the largest display size (27″ iMac/Thunderbolt Display) will be, it will be large enough that 512×512 px icons would be considered too small, at least under some circumstances.

    Also, a 20% resolution bump may not be sufficient to make it an important-enough marketing point.
  • Matthew Gonzales Landry

    The only thing that doesn’t make sense in all this is the quadruple-sized UI elements showing up in Lion and Mountain Lion. You can already switch on HI-DPI mode in Lion and see what happens when it assumes your display is “Retina” … on a 1920×1080 screen it renders the UI as if it were a high pixel density 960×540 display. There is no reason to assume that this isn’t what Apple is going to do … basically allow you to switch on a HI-DPI mode (or set it like that by default) on any display over a certain threshold. And considering that you have the equivalent of a 960×540 display at 1920×1080, the screens will HAVE to be larger than that. Your arguments were well reasoned, but ignored this basic fact … support for quadruple resolution screens is already in OS X, and existing screens are simply too small to accomodate.

    The battery life is a non-issue, for exactly the reason you claimed it was a problem … Apple squeezed a 70% larger battery into the iPad, and the differences were marginal: slightly thicker and heavier. You only notice the difference on direct comparison. Given that the Macbooks will have a little more room to play with, Apple can increase the battery life and probably shrink the devices, and still quote the same battery life numbers as today.
    When it comes right down to it, your article is too obsessed with what qualifies as a “retina” display, and ignores all of the details that we already know. There is no reason to assume that Apple will not be shipping out displays at least as high-res as what’s in the iPad, because Apple has already demonstrated that they are capable of doing exactly that.

    I can see Apple doing what Mr. Brownlee said. When you increase the pixel density, you also decrease GPU performance. Look at the massive A5X SoC! Apple builds thin and light computers. Apple even tried to make the iPad thinner than it was, it’s just that Sharp could buil the new backlight system in time.

    I was excited to see all the retina evidence at first, but that was just me being greedy. I’d much rather have a more efficient computer than a massive resolution. Don’t forget that the resolutions on these computers that would be retina-quality are still fantastic. I’d like a little more buffer room for the 15″ MacBook Pro, but besides that, I don’t think much needs to change. Someday, it’ll be really cool to have invisible pixels from any viewing distance, but unil then, I’m happy with the figures posted here.

  • mr_bee

    The only thing that doesn’t make sense in all this is the quadruple-sized UI elements showing up in Lion and Mountain Lion. …

    I would say that this could be explained away by noting that the icons in OS X have *always* been far bigger than they need to be for the resolution displayed.  Apple was using 256×256 icons when Windows was still using 32×32.  So the presence of icons that are larger than needed is not necessarily probative. 

  • Brandon P. Turner

    “…there is no magical number of pixels per inch that automatically equates to Retina quality.”

    There’s a formula for determining how many pixels per inch a display needs to be to achieve ‘Retina’ quality, …”

    Wait. There is or there isn’t? :/
  • Brandon P. Turner

    “…there is no magical number of pixels per inch that automatically equates to Retina quality.”

    There’s a formula for determining how many pixels per inch a display needs to be to achieve ‘Retina’ quality, …”

    Wait. There is or there isn’t? :/

    Maybe I’m just misunderstanding. Sorry.

  • Ryan Villanueva

    Frankly, I would just be happy if Apple started using IPS display tech on their MacBooks. If the iPad and iPhone has them why not the higher end Macbook Pros?

  • Ryan Villanueva

    Frankly, I would just be happy if Apple started using IPS display tech on their MacBooks. If the iPad and iPhone has them why not the higher end Macbook Pros?

  • GeekLogan

    I find it likely that Apple will use the space reclaimed from loosing the optical drives to increase the battery size.

  • Bob Forsberg

    Its all a prelude to AppleTV and iMacs doing double duty for 4K visuals of movies and TV shows. If you know of a big package store selling big screens and nothing Apple it will not be there in 3 years.

  • macmark_de

    iOS is just like Mac OS X resolution- and device-independent; you can see that with ease by looking at an iPhone or iPad with and without Retina display side by side.

About the author

John BrownleeJohn Brownlee is a Contributing Editor. He has also written for Wired, Playboy, Boing Boing, Popular Mechanics, VentureBeat, and Gizmodo. He lives in Boston with his girlfriend and two parakeets. You can follow him here on Twitter.

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