Multi-camera phones are the norm now, but the modules they use have a traditional design, one optimized for size. This limits the focal length - which, true to its name, is a measure of the distance from the lens to the sensor - meaning that telephoto cams rarely go above 2x zoom (and we're yet to see one go above 3x). A new breed of telephoto cameras has emerged at this year's MWC (we've seen prototypes earlier, but no mass market products). Yes, we're talking about the periscope type cameras, which are called that because light is reflected 90°. This guides light along the width of...