The new phones just keep coming at the Mobile World Congress in Barcelona. Sony has unveiled four new handsets at the show, including the Xperia XZ Premium flagship. New Atlas visited Sony's booth to check them out in person.

The XZ Premium is claiming two smartphone firsts: A display that boasts both 4K resolution (2,160 x 3,840 pixels) and HDR support, along with a "super slow motion video" mode that records at 960 frames-per-second, an unprecedented level of slow-mo for a phone.

Extra memory built into the camera that enables this super-super-slow-mo reportedly ensures there's no lag at all when you hit the shutter button.

Unfortunately we weren't able to test any of these features at MWC – Sony's demo units were either locked away behind a case or switched off, with representatives saying the software isn't ready to be tested.

We did get some hands-on time with a turned-off XZ Premium though, and can report the build lives up to its "premium" tag. It's lightweight, comfortable to hold in one hand, and stylishly curved just like Xperias past.

It's also a real fingerprint magnet because of its glossy back and sides – we've seen quite a few devices that attract fingerprints like crazy, including the Tab S3, but this sets a new high watermark. You'd need to wear gloves or keep a soft cloth permanently on your person to make sure the XZ Premium stays looking its best.

There is a black option to go with the silver one shown in our photos. It's just as glossy, though it is a bit harder to see fingerprints on.

We did preview the 5.5-inch 4K HDR display from the outside of a display case, with Amazon Video providing the content. We doubt the resolution makes that much difference but the HDR certainly makes colors stand out, with contrast levels that make every part of the picture crisp and clear.

This 4K HDR standard is Sony's own set of specs for High Dynamic Range: It's not the same as Dolby Vision (as seen on the LG G6) or the HDR 10 spec included as part of the Ultra HD Premium standard (set by the companies of the UHD Alliance, of which Sony is one).

Format wars aside, we came away impressed with the XZ Premium's display, although it was difficult to take a close look and we didn't have anything to directly compare it to. Under the hood the phone boasts specs that are going to be hard to beat this year, including a Snapdragon 835 CPU and 4 GB of RAM.

We had some time with the Sony Xperia XA1 as well, one of two mid-rangers also unveiled during MWC (the other being the slightly larger XA1 Ultra). Again, Sony's solid craftsmanship was on show, though this phone definitely has a cheaper feel to it than the XZ Premium flagship (the retail price is expected to be significantly cheaper too). Video content still looks great though thanks to the virtual absence of any side bezels.

Sitting between the XZ Premium and the two XA1 phones – in pricing, specs, and quality – are the XZs (no, we don't know who's in charge of naming phones at Sony either). There were no XZ demo units available to play around with at Sony's booth, although we can tell you the phone includes the same slow-mo camera as the XZ Premium but drops the 4K HDR display spec.

In terms of design and aesthetics, Sony hasn't changed its formula much this year, and so you'll probably already know whether these phones appeal or not. We were impressed by the 4K HDR though, and with LG integrating Dolby Vision into its new phones too, we look set for another quality jump in smartphone displays thanks to the wonders of HDR.

Pricing and availability is yet to be confirmed for these phones, as you might have guessed considering no working XZ Premium models were available to test. Sony representatives said the devices should be out during the first half of 2017.

Product pages: Sony

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