Oppo did not come to the Mobile World Congress with a phone this year, but with a promise. This promise is a lossless 10x optical zoom, which you can get with a new three-lens camera system recently introduced by the company. I've tried it myself, and while I do not want to claim that the results are as flawless as a dedicated camera with a true optical zoom system, this is definitely the best we can get from the seemingly insurmountable challenge we have can master real zooming in the narrow limits of a smartphone.
The most important component of Oppos System is a periscope setup in the phone: light enters through a lens, is reflected by a mirror into a series of additional lenses, and then arrives at the image sensor, which sits perpendicular to the body of the phone. This is responsible for the telephoto lens in Oppo, which has an equivalent of 35 mm by 1
For the prototype device Oppo offered for testing, the camera software was locked to allow only simple still images. I was not able to shoot video, although it is encouraging to find out that Oppo has expanded both the main camera, which will have a powerful 48 megapixel resolution, and the telephoto lens with optical image stabilization (OIS). The closer the zoom, the more necessary OIS becomes, so this is a must. I am also pleased with the fact that Oppos Telephoto-OIS is rotated by a fraction of a millimeter due to the user's unconscious hand movements.