Smartphone 4K HDR in action: check out the Sony Xperia XZ Premium's display

Sony's latest high-end smartphone just made its debut at MWC 2017, and its biggest feature is a bit of a blast form the past. Sony was ahead of its time back in 2015 when it introduced the Xperia Z5 Premium, the first smartphone ever to squeeze a 4K screen's worth of pixels into a tiny, pocket-friendly form-factor. While other manufacturers have been content to top out at quad-HD ever since, Sony's stepping back up to the plate with its sophomore 4K smartphone effort, introducing the new Xperia XZ Premium.

We already got an early look at this 4K phone, but our initial run-in was a bit limited, with the hardware not quite ready to be powered-up. Since that takes a bit of the air out of the whole point of having a fancy new display, we absolutely had to circle back around on the MWC show floor to track down fully-functional Xperia XZ Premium handsets.

With the phone now ready to let loose with its 4K HDR action, we're finally able to see just how incredibly sharp, detailed, and colorful this screen appears in person. In addition to getting to check out Sony's familiar Android UI on the ultra-high-res new screen, we also watched some demos of how the new 4K support for HDR video compares with the old Z5 Premium, which lacks that HDR mode.

As we'd only expect, there's a pronounced difference in image quality between these two handsets. They both look really, really good – don't get us wrong – but brightness, contrast, and even color saturation pulled ahead on the Xperia XZ Premium's new 4K HDR display.