That's why Perceptiv Labs developed Shift. It's a system that allows a DJI or 3D Robotics quadcopter's motorized camera to automatically keep a tagged subject centered in the frame, letting the user concentrate on flying.
The Shift hardware consists of a processor that is mounted on the drone (and plugged into its autopilot system) along with a "Shift Eye" that is mounted adjacent to the camera lens – that Eye lets both the processor and the user see what the camera is seeing. The combined weight of the two components, including battery, is less than 200 g (7 oz). One charge of the battery is good for about an hour of use.