I don't fly with my iPhone anymore, I went to the macgyver mod. Now I have a 2.4 digital controller and have control up to 800ftI have the same drone but haven't taken it that high up yet. I keep thinking it will loose connection & fall on the neighbors house lol. I fly it in my house more than I do outside. I'm fortunate that I have several batteries for it as they don't seem to last very long..
It's the wide angle lens causing the curve.That is cool! You can almost see the curve of the Earth!