The recently announced Sony Xperia Z5 Premium can boast of being the world’s first production smartphone with a 4K display, by way of a 5.5-inch screen and 3840 x 2160 pixel resolution, equating to an unparalleled 806 pixels per inch.
However, Sony also claims the Z5 has a two-day battery life, defying conventional wisdom that a higher-resolution screen consumes more power. To achieve this feat, Sony engineered the Z5 to only display photos and videos at the ultra-high 4K resolution, while all other content is displayed at 1080p Full HD for battery conservation purposes.
Otherwise, the Z5′s other selling points include complete waterproofing, 4K video recording with image stabilization, a 64-bit octa-core Qualcomm Snapdragon 810 processor, and a 23MP rear camera. While pricing and availability is yet to be announced, you can find more details here.