Sony recently launched its top-notch Xperia Z5 Premium as the world's first 4K smartphone, but most content doesn't appear in 4K.
When it comes to actually viewing 4K content on the Xperia Z5 Premium, there's a catch. The smartphone displays media such as videos and photos in 4K, but will otherwise show content in 1080p. While some users may feel cheated, there's a good explanation for this.
Packing a whopping 4K resolution on a smartphone sounds like a challenge, and the Sony Xperia Z5 Premium delivers: you get an insane resolution of 3840 x 2160 on a 5.5-inch screen, which translates to 806 pixels per inch (ppi).
Such a high pixel density is bound to take a toll on battery life — yet Sony claims that its Premium flagship can last up to two days on a single charge. As it turns out, the fact that the smartphone shows most content in 1080p is closely related to the battery life. To preserve battery rather than drain it instantly, the 4K smartphone defaults to 1080p whenever you're not viewing media content.
"The Xperia Z5 Premium features a 4K display with a resolution of 3840 x 2160 pixels based on SID Standard and enables all video and image content to be enjoyed in 4K resolution," Sony explained in a statement to Phone Arena.
"All other content is displayed at 1080p or lower resolution in order to optimize the performance and battery stamina for this device, ensuring you can enjoy the 4K resolution when you need it most."
The handset packs a beefy 3,430 mAh battery under the hood, but it would not be able to deliver the promised two-day battery life if it displays all content in 4K. With this switch to 1080p whenever videos or photos are not involved, the smartphone does achieve the promised battery life.
That said, some will argue that even a QHD (2K) resolution of 2560 x 1440 pixels might be overkill for smartphone displays, which further underscores the question of whether a 4K display that doesn't even show all content in 4K was really necessary. Nevertheless, the Sony Xperia Z5 Premium has stirred plenty of interest and its commercial launch is highly anticipated.
