Periscope cameras are a way to provide long focal lengths in the slim form factor of a smartphone. But how do they work? A video that shows the disassembly of Oppo Reno camera could shed some light on that. The periscope module measures only 23.5 x 11.5 x 5.73mm. It's thin enough that it can fit into phones without creating a major hump. It's quite small overall, so it doesn't take up too much of the internal volume. The module consists of three main parts: prism, lenses and sensor. The lenses come out as a unit, they are a special "D-Cut" design that helps keep the module as thin as it...