Sony’s flagship Xperia 1 smartphone, long the choice of photography nerds, vloggers and camera enthusiasts, has added what is perhaps its most stand-out feature yet: a variable optical zoom. With what Sony says is the “world’s first true optical zoom lens” on a smartphone, the Xperia 1’s camera lets you zoom in without the usual pixelation that comes from pinching to zoom on other smartphones. The fourth generation of the Xperia 1 has a variable focal length of 85 to 125 mm, which translates to a light zoom ideal for portraits at 85 mm, with room for more of a close-up up to 125 mm. This zoom …