Even if it weren't the world's first 4K phone, the Sony Xperia Z5 Premium has a lot going on

4K or not 4K -- that is the question. Sony has revealed what it claims is the world's first smartphone with a 4K display, the Sony Xperia Z5 Premium. But can our eyes even cope with such an eye-popping screen at such a pocket size?

Before we get into the 4K debate, it's worth pointing out that even without the 4K screen the Z5 Premium is a heck of a phone. Going on sale in November, the Z5 Premium is a slightly larger and classier version of the new Xperia Z5 and its smaller sibling the Z5 Compact. It's certainly a slick proposition: the 5.5-inch Premium is packed with features and wrapped up in a luxurious mirrored glass package.

The case comes in gold, black or mirror-like chrome. The shiny, reflective casing looks great but it's quickly marred by fingerprints, so keep a cloth handy. Alternatively, you can hose it down -- like most of Sony's recent smartphone lineup, the Z5 Premium is waterproof. Drop it in your Martini and it will continue on like nothing happened. Take it in the shower, and your only worry will be the water going cold.

It's also very thin and light, and the screen fills most of the front face to keep the overall size down.
See how it compares other large-screen superphones, like the Samsung Galaxy Note 5, iPhone 6 Plus and LG G4.

A new feature on the trio of Z5 phones is a fingerprint scanner, but it might take you a minute to spot it by looking at a picture. Give up? It's in the power button. Instead of a sensor in the home button (like the iPhone) or on the back where you can't see it (like the Samsung Galaxy S6) the Z5 phones boast a more subtle sensor in the button on the side. It looks great, but does it work? We'll find out when we spend more time with the phone for our forthcoming full review.

 

Putting the 4K in phones

The Z5 Premium's claim to fame is that it has an eye-scorching 4K screen. 4K is the next big thing in display technology, promising loads of extra detail packed into movies, games and videos whether you're watching on a 4K television or filming on a 4K camera. It's so new, there's still a shortage of things to watch: Netflix has some shows in 4K and a few live events are filmed in 4K for broadcast.

Some phones already shoot 4K video -- including the Samsung Galaxy Note 5 and Sony Xperia Z3+ -- that you can watch on your 4K TV. But the Z5 Premium is the first phone that allows you to shoot 4K video and then watch it back at full resolution on the same device. The Z5 Premium also upscales less detailed video from Netflix or YouTube or other sources to 4K.

The big question is whether there's any actual benefit in having a 4K phone. A vast amount of extra detail in a huge TV is one thing, but it's open to debate whether at this smaller size you'll actually be able to see the difference between 4K video and high definition video, which is already pretty pleasing to the eye.

We'll try and answer that question when we've spent more time with the phone in our full review, coming soon. During our limited time with the phone so far, we certainly found that Sony's sample 4K footage looked gorgeous...but so does the full HD video. Ultimately, trying to work out whether video is jawdropping or just eye-popping is quite a nice problem to have.

Article originally shared on www.cnet.com