Your iPhone already comes with power cameras for selfies and serious videos. With this ULANZI DOF Adapter with Sony E Mount, you can do more with it. It lets you attach full frame lenses to your iPhone to do more with it. The ULANZI DOF Adapter is ideal for fast lenses (f0.9-f2.8).
Thanks to this mount, you can get more creative with your iPhone camera. It does come at a cost though. For instance, the DOF adapter turns your image upside down, so you need an app to address that. vignetting, barrel distortion and chromatic aberration are other issues that you may have to deal with.