Q1. With all the material and discussion I've heard on the Phantom 4, I've not yet heard or seen anything relating to calibrating it's compass. Is this now a thing of the past? Q2. I've seen a couple of shots where the Phantom 4 is rotating around a subject when the subject is moving… Is this an specific P4 function/fly manoeuvre or is this just a combination of the Track Subject and the user using the sticks to do the orbit? Q3. Since the radio controller uses a Lipo battery too, does this need to be left partially charged in the same way the aircraft battery does? Thanks in advance..