At IFA in late August, Sony surprised everyone by unveiling the Xperia Z5 Premium — the world’s first smartphone with a 4K resolution display. However, it was soon revealed that the handset only takes advantage of the higher resolution display while displaying photos and videos and otherwise renders the UI at Full HD resolution to achieve a balance between performance and battery life.

Now, Sony has posted an in-depth explanation about the 4K display on the Xperia Z5 Premium to clear some of the confusion surrounding it.

In the blog post, the company confirms that the Z5 Premium uses its 4K display to its maximum potential only when you are watching a 4K content — either shot through the phone or by streaming it through third-party services. All other content, including apps and the home screen, are displayed in Full HD (or lower) resolution.

Sony has also added its own upscaling feature inside the Xperia Z5 Premium to make sure all the content within the company’s own Movie and Album applications are optimised for the device. The upscaling feature also works for video streaming services like Netflix and YouTube.

So, if everything is rendered at Full HD or lower resolution — except for certain content — what is the benefit of having a 4K display, you ask?

Below is what Sony had to say about this.

There’s a few reasons – first up, after extensive user research and testing we found that rendering entertainment content in 4K, but still being able to access and use all the other great Sony smartphone features as normal without compromising on battery life, was an absolute priority for users.

Secondly, many third-party apps are not designed or capable of running at 4K resolution (yet), but as Xperia Z5 Premium’s display hardware has a 3840×2160 resolution (4K SID standard) with 806ppi, we feel we’ve created a future-proof device for the imaginations, developers and apps of the future.

Sony also clarifies in the post that since Lollipop does not natively support 4K screen resolution, all screenshots on the Z5 Premium are taken at Full HD resolution.

If you are interested in buying the Xperia Z5 Premium or are just interested in its 4K display, head over to Sony’s website to read the company’s full explanation about it.