https://www.theverge.com/2019/2/23/18237269/oppo-10x-optical-lossless-zoom-camera-phone-periscope-mwc-2019

Oppo has come to Mobile World Congress this year not with a phone, but with a promise. That promise is a lossless 10x optical zoom that you’ll be able to obtain from a new triple-lens cameraphone system the company just unveiled. I tried it out from myself, and while I wouldn’t say that the results are quite as pristine as having a dedicated camera with a true optical zooming system, this is definitely the closest we’ve yet come to conquering the seemingly insurmountable challenge of injecting real zoom into the tight confines of a smartphone.

The key component to Oppo’s system is a periscope setup inside the phone: light comes in through one lens, gets reflected by a mirror into an array of additional lenses, and then arrives at the image sensor, which sits perpendicular to the body of the phone. That’s responsible for the telephoto lens in Oppo’s array, which has a 35mm equivalence of 160mm. Between that lens, a regular wide-angle lens, and a superwide-angle that’s 16mm-equivalent, you get the full 10x range that Oppo promises.