The iPad's screen is so good, Apple's had to invent a new
word for it: 'resolutionary'. The display is the sharpest screen you'll find in
any tablet, and it's a technical marvel: Apple has pushed display technology to
its very limits, delivering something that looks like it's been beamed in from
the future.
But is there any substance to the style? Will the Retina
display mean better, brighter apps, or will our iPads struggle as apps become
bigger and more bloated? Let's find out.
What Retina means
When Apple talks about a Retina display it's not referring
to a worldwide standard or a set of specifications. It's actually just a
marketing term, and it simply means that the screen has sufficient pixel
density, so that when you look at it normally, you can't make out all the
individual pixels.
The key word here is 'normally', because that differs from
device to device. The new iPad's screen doesn't have as many pixels per inch as
the iPhone 4S, but it's still a Retina display. The difference? Distance.
Apple reckons that the normal viewing distance for a mobile
phone is around 10-inches, but for an iPad the distance is 15-inches. To
deliver a Retina display at 10-inches you need to pack in more than 300 pixels
per inch, but at 15-inches you can get an identical effect with considerably
fewer pixels. The iPhone 4S has 326 pixels per inch, and the new iPad delivers
the same quality with 264. At least that's what Apple would like you to think.
But is it actually true?
We think it is: in everyday use, the new iPad's screen is as
crisp and as clear as our iPhone 4's, with no noticeable jaggies - or at least,
none in apps that have been updated to take advantage of the new iPad's extra
pixels. The resolution is twice that of the iPad 2: it's running 2048x1536, and
the iPad 2 runs 1024x768. That means the iPad has more pixels than a 1080p
high-definition television, which maxes out at 1920x1080.
The new iPad's display is miles better than not just today's
rival tablets, but tomorrow's: current Android tablets typically run 1280x800
displays, and the forthcoming full-HD tablets from the likes of Lenovo and Asus
run at the same resolution as HD TVs, 1920x1080. Full HD in a tablet is pretty
impressive, but at 224 pixels per inch it's still a considerable way behind the
iPad - and the iPad is shipping now, not at some unspecified point in the
future.
The display isn't just better in terms of pixels. According
to Dr Raymond Soneira, president of display calibration experts DisplayMate
Technologies, the new display has better colour saturation too: "a
virtually perfect 99% of the Standard Colour Gamut… [colours] are 'more
vibrant' but not excessively so or gaudy like some existing OLED
displays."
The new iPad is "most likely better and more accurate
than any display you own, unless it's a calibrated professional display. In
fact, with some minor calibration tweaks the new iPad would qualify as a studio
reference monitor."
On paper, then, the new iPad has the best display around.
Does it matter? Many tech specs don't matter much: on paper the iPad is often
trounced by rival devices with more horsepower, more memory or an extra bit to
plug things into, and yet we all know it's the best tablet money can buy.
Is the Retina display a real step forward, or does it just
give Apple a few numbers to annoy the competition with? We think it's the
former. The Retina display is the latest step in Apple's plan to make
technology disappear. The first step was iOS and multi-touch: as endless
YouTube clips of iPhone and iPad-using babies demonstrate, you no longer need
to learn computing to use a computer. The next step is to make the computer
itself disappear, and the retina display does that.
More than a pretty face
Take magazine apps, for example. On non-Retina displays even
the most beautiful magazine app is still a bit computer-y: the screen can't
deliver text that's as sharp as printed text, or images as sharp as printed
ones.
A Retina display can. You're no longer reading a magazine on
a screen; you're simply reading a magazine. It's more effective than on the
iPhone, too, because the bigger screen means you're not scrolling every four
words. Email and ebooks are easier to read, app interfaces look more realistic,
photos are brighter and sharper and Flipboard feels like it's been sent from
the future.
When you think about it, it's really quite extraordinary.
It's also extraordinarily difficult to make. 264 pixels per inch is pushing the
limits of current TFT display technology. However, Samsung (who make the iPad
screen) have recently announced
a 5-inch screen with a full 1080p resolution. This weighs in at a mighty
440 pixels per inch but isn't currently available in any products.
Achieving retina resolutions with current TFT technology
isn't easy. The more tightly you pack the pixels, the lower the display's
aperture ratio becomes. The aperture ratio is the ratio between the pixel's
transparent area and the whole pixel area including wiring; the smaller the
ratio, the less light gets through. To compensate for this, Apple has been
forced to double the number of LEDs in the iPad's backlight, which uses 72 LEDs
and requires two and a half times more power than the backlight in the iPad 2.
The other issue with Retina displays is that the more
tightly you pack the pixels, the more likely you are to encounter unwanted
capacitive coupling, which is when signals jump from one component to another
and cause interference and image artefacts. To address this Apple has used
Super High Aperture (SHA) technology, which places a layer of resin between the
pixels and signal lines to keep everything in its right place.
No comments:
Post a Comment