Sony’s Z5 – the first smartphone to feature a 4K-resolution screen.

Sony’s Xperia Z5 Premium can both capture video in “ultra-high definition” quality and then play it back on its 5.5in (14cm) display without downgrading the footage, as all their Z5 handsets feature a new 23 megapixel sensor camera module. The Z5 Premium’s ultra impressive screen which has  4K resolution of the 5.5-inch display gives an…