Hi, it's HandyAndy Tech Tips here, and it seems that phone manufacturers just don't
know when enough is enough. I'm talking, of course, about the race to produce the highest
resolution screen possible, and it looks like Sony has just accomplished a major feat in
this regard. So I present to you the new phone which everybody's talking about. Yep, it's
the Sony XPERIA z5 Premium, and one of its most amazing features is that the screen has
a 4K resolution - that's 3840 x 2160 pixels. In other words, this phone has more pixels
than a large 50-inch TV had just a couple of years ago. Wow. So, how did we even get
to this point? How have phone screens evolved this much? Well, to understand this, we need
to look at PPI. It stands for "pixels per inch", and it's basically a measure of the
density of pixels in a phone screen, or any screen really. So the higher the PPI, the
closer the pixels are packed. So, looking at the original iPhone for a minute, which
was released back in 2007, it had a 3.5 inch screen with a 480 x 320 resolution on it.
So that was 163ppi. And surprisingly, the first Android device, the HTC Dream (which
was released back in 2008), actually one-upped the first iPhone, with 180ppi. But of course,
Apple are never a company that wants to be left behind, and in 2010 they released a product
which would actually redefine the entire display industry. And what was it? The iPhone 4. This
had a Retina display, it was actually a new term at the time, with 326 pixels per inch.
Just as a bit of a reminder, that was actually a doubling of the original iPhone's PPI. So
the Retina display was released to rave reviews. People called it an "outrageous" resolution
and "stunning". And of course, this was enough to put Apple's competitors on the offensive.
In other words, all hell broke loose basically, and there was an arms war to see who could
get the highest resolution display. And that's culminated in this new Sony phone having 806PPI,
or, in terms of resolution, as many pixels as an expensive TV. So the question that you
might be asking, and quite reasonably as well, is: how can you actually see anything on this
extremely high-res phone? I mean, we've all, or most of us anyway, we've had experiences
with using those really high-resolution Windows laptops. You know, the ones which have a 13
or 14 inch display, and a Full HD resolution on it. And the text is just simply tiny! I
mean, you almost need a magnifying glass to read it! So how do these phones scoot around
that problem? Well essentially, they use something called DPI scaling, and it's quite simple.
Basically how it works is that everything on the screen is twice as large as it normally
would be. (I bet you didn't know that the explanation would be that good, hey?) But
to be more specific, if you set the scaling settings to 200% on a 4K display, then you
get the illusion of using a 1080p display. So the screen has twice as many pixels, but
everything actually looks the same physical size. So you're probably thinking: yeah, alright,
that stuff sounds pretty clever. But what's the point of having a 4K screen when you're
just going to make it look like a 1080p one? In other words, what are the benefits of High
DPI? Well firstly, and this is one which comes up a lot, you can't see the pixels at a normal
viewing distance. But what is a normal viewing distance? What is "normal"? Well, when Steve
Jobs was introducing the first Retina iPhone, he claimed that "there is a magic number around
300 pixels per inch that, when you hold something 10 or 12 inches away from your eyes, is the
limit of the human retina's ability to differentiate the pixels". Most people believe what he said,
but there has been some criticism about it, because the calculations were based on 20/20
vision. In fact, there was an amusing article that I read a while ago, which basically said
that all smartphones should have 900PPI displays, 300PPI was completely inadequate, because
most younger people actually have far more than 20/20 vision. But honestly, despite all these arguments
and controversy, it can still be said that the pixel structure on a Retina screen is
less visible than on a non-Retina screen, even if it's not completely invisible. And
it turns out that having a smoother looking screen is a big benefit when it comes to virtual
reality headsets. Just take the example of the first Oculus Rift Development Kit, which
was put out a couple of years ago now. It had a 1280 x 800 pixel display. Now, obviously,
this was a bit of a problem, and a lot of people complained about this weird "mosquito
net" or "screen door" effect, where you could actually easily see the pixel structure of
the screen due to the fact that you looked through two magnifying lenses. Now if you
put the XPERIA z5 in one of the phone-based VR headsets, like Google Cardboard, then there
should be none of those problems, no screen door effect. And in fact I'm really looking
forward to seeing what 4K brings to the VR experience. So how about people who just use
their smartphone as a phone? Would there be really any advantage to having, say for example,
an 800ppi display (which would be 4K) to having a 400ppi (which would be 1080p)? Well, in
my personal opinion - now I'm basing this on a couple of factors, having a 5 or 6 inch
device, and viewing it at a normal viewing distance - no. You're perfectly fine with
a 1080p phone. And it's worth remembering that there's far more that goes into a quality
screen than just the resolution. There's the type of panel - whether it's an AMOLED or
just a standard LCD, there's the contrast ratio, there's a lot of things, and colour
accuracy. So, personally, if I was getting a good smartphone, I would prefer getting
a nice AMOLED with good colour accuracy in 1080p, rather than 4K. So I'm HandyAndy and
thanks so much for watching my video. Please subscribe if you want more tech videos, because
I've got heaps more of them coming right up!