Sony on Xperia Z5 Premium: not much 4K content anyway

Despite the practically same old design, Sony might have finally hit some of the right notes with the Xperia Z5, especially after DxOMark crowned it king of the mobile photography hill. The Xperia Z5 Premium, on the other hand, despite boasting the world's first 4K smartphone display, is proving to be a harder sell. After being discovered to be using only 1080p for most of its operations, something it conveniently failed to mention at first, Sony is now trying to come clean about the how 4K is really being used on the high-end smartphone.

You have to wade through pools of marketing-speak, but in the final analysis, the Xperia Z5 Premium's full 4K capabilities only kick in under two circumstances. First is video and photos you've taken in 4K using the smartphone. The second, which is a bit more vague, covers content from Sony's Movie and Album apps and streaming services like Netflix and YouTube that offer 4K content.

That last part is actually a bit ambiguous. Sony would later say that not all 4K content from streaming and subscription services are optimized for use on a mobile device. This seems to imply that in majority of these cases, lower resolution version, perhaps Full HD or even 2K, is being used and the smartphone simply upscales that to 4K during playback.

In all other cases outside those two above, the Xperia Z5 Premium switches to 1080p resolution. Even when taking screenshots, it only uses Full HD. Sony justifies this resolution juggling in the interest of preserving battery life, which is, of course, understandable. On the question of whether upscaling process takes up battery and memory, Sony gives the perfect PR answer by not answering directly and simply praising the virtues of the smartphone's two-day battery life (under STAMINA mode) and its microSD card slot.

But if you read between the lines, this is practically an admission from Sony that there isn't really much 4K content available to take advantage of the smartphone's killer feature. And in cases where 4K is indeed available, they aren't optimized for mobile consumption anyway. So why bother with a 4K smartphone this early in the game anyway? For Sony, perhaps there are two reasons. The first is for future-proofing, in the eventuality that 4K mobile content becomes ubiquitous. Maybe in two years or so. The second is, of course, to be able to say "we were there first".