Good day all. A brief intro as a newbie. Based in the NE of England, I'm approaching retirement from the Royal Air Force as an internationally-certified Imagery Analyst. The natural thing for me was to keep involved in aerial imaging and I recently bought a Phantom 2 with ancilleries including the GoPro3 Black and the Zenmuse H3-2D gimbal. In the short term I'll be gaining handling experience with the platform and sensor acquiring content for my portfolio before embarking on purchasing DJI's S800 Evo with the likely intention, in the long term, of starting my own business after obtaining appropriate UK (CAA) official certification. Looking forward to draw as much knowledge from you and get "read-in" with published advice sought from this forum in the meantime. No doubt, I'll be posing questions as I go along. As a starter I do; however, have one question one's hoping could be answered (please stick with me on this one). I'm looking to work out by using the Phantom, the ground coverage/scale of still imagery (in metres) collected in the vertical (90 degree) position/angle using the GoPro3 Black at intervals of 20 metres in height. Example being that if the Phantom was at, say, 60 metres AGL, the scale (ground sampling distance) of still imagery obtained from the GoPro3 will be XXX metres in the horizontal plane, XXX metres in the vertical plane. If the Phantom was at 100 metres AGL, still imagery collected will be scaled at XXXX metres in the horizontal plane, XXXX metres in the vertical plane. I hope you know where I'm coming from on this? If anyone can give me a rough, or indeed accurate reply this could potentially save me some testing/trialing time. Thanks all.