Sensor Size
When smartphone makers mention the specs of their lens, they usually equate it to a 35mm equivalent. This means they are comparing it to a full-frame camera sensor that is 35mm across. As most phone sensors are around 4 or 5mm across, this is a big difference. Make sure when matching footage for VFX to get all the camera data you can, as most 3D applications can account for sensor size in the camera object. Lens type, focal length, f-stop and camera model per shot are the key ingredients from which a camera solve can be derived.