Is the Sony Xperia Z5 Premium’s 4K screen really necessary?

Ultra high definition on a smartphone screen is a hype, and that’s all, says Tein Hee Seow

You can’t tell the difference between a full HD or 4K screen on a smartphone.

At least, that’s what journalists realised during Sony Mobile’s press conference at IFA 2015. Right after the press conference, the horde of journalists made the mad dash for Sony's Xperia Z5 Premium, and started talking up the insane sharpness of the 4K screen. Except, this story on Mashable highlighted a major blunder - the phone everyone was looking at was, in fact, the Sony Xperia Z5, armed with a mere (by comparison) full HD screen. 

Epic. Burn. And cue the awkward silence for everyone in the room.

Point being, squeezing millions of pixels into a screen the size of your palm isn’t going to do wonders. In our day-to-day, our eyes can only discern that much details. Pay less attention to the screen and you might not even see the difference in screen quality between two phones with 720p and 1080p displays.

The end goal of an ultra high definition resolution is to make you feel that you’re look at at the world’s sharpest screen. Sony did succeed and impressed us during our hands-on.

Yet, putting the Xperia Z5 Premium against its full HD sibling, the Xperia Z5, has also shown the limitations of more pixels. Sure, the 4K smartphone has a higher PPI. But at what cost? A dimmer screen because there’s just too many pixels for the backlight to counter? Or perhaps a lower battery mileage, the bane of all large screen and high resolution smartphones? For that last point, Sony Mobile assures it isn’t a problem with a 3430mAh battery that serves up to two days of juice. But we won’t know till we’ve properly stress test the 4K-ready smartphone.

That’s not to say 4K resolution isn’t what everyone should be aiming for. But it must be deployed on the right platform. Putting it on a smartphone screen that’s no larger than six inches is just plain overkill. Now, on TVs that feature massive sizes of at least 40 inches and above, that makes perfect sense. The jump from full HD to 4K resolution for TVs is justifiable, especially with the upscaling technology that makes full HD movies look absolutely amazing on the 4K screen.

While Sony proves that it can and will make a smartphone with a 4K display, it needs to answer one question - is it really necessary? First, there’s still a lack of ultra HD content, a problem shared by 4K TVs. Second, just because it can, doesn’t mean it should and in the end, bump up the manufacturing cost. While the Xperia Z5 Premium’s price hasn’t been officially announced yet, the “premium” term is a hint of a phone with a four-figure price tag.

But maybe, just maybe, Sony’s early entry into the 4K game for smartphones might spur others to do the same for their next flagship. And with it, 4K smartphones might not command a premium price.