The Z5 Premium does bring enough novelties to the series to deserve its name. The first ever 4K display on a smartphone is surely a catchy headline feature, but we shouldn't also miss the fact that it comes spread over a display that's 5.5-inch in diagonal, a size that was so far missing from Sony's flagship portfolio.
In practice, the Z5 Premium has reasonably thin side bezels with some more meat top and bottom but overall the typical Xperia proportions. The front has the stereo speakers, the selfie camera, a couple of sensors and the primary mic hidden below the bottom grille.
Sony Xperia Z5 Premium is the first smartphone to feature a 4K display. To be more specific it utilizes a 5.5" IPS panel of 2160 x 3840 pixel resolution. The resulting pixel density of 806ppi is well above anything we've seen on a smartphone or even a tablet for that matter.
4K is another name for UHD resolution or 2160 x 3840 pixels. That's an awful lot of pixels - something along the lines of 8.3 million of them. Phones so far had only been able to go as high as 1440 x 2560 pixels (3.7 million pixels). The screen in the Xperia Z5 Premium is the first of its kind in a smartphone. It's an amazing engineering feat and it's surely a challenge for any sort of a mobile hardware to pump out so many pixels to the screen.
The Sony Xperia Z5 Premium is powered by a beefy 3,430 mAh battery sealed-in as expected. It scored an overall endurance rating of 66 hours, which is above average and certainly impressive, having in mind there is a 8M+ pixels on this screen to light up.
An endurance rating of 66 hours is still above average and it means that the Z5 Premium should be more than happy to offer that many hours of our test pattern usage.
Sony has decided to equip the whole Z5 family with a new 23MP camera. That means that the latest Premium sibling should offer a pretty comparable photo quality. Sony might be marketing the new camera as simply a 23MP one, paired with an f/2.0 24mm-equivalent wide-angle lens, but there is actually a lot more going on behind the scenes.
With 23MP camera and powerful Snapdragon 810, the Xperia Z5 Premium has all the required prerequisites to do 4K. It definitely lives up to those expectations, producing pretty impressive results. Videos come out with a lot of detail, nice colors and smooth motion.