The campsite in Edinburgh was underneath the flight path for the airport. Given that I had to fit the camera in between my face and my little finger, let's say that my little finger is worth 1.5 degrees. So the plane subtends 3 degrees of my vision, which is 3/360 x 2pi = 0.05 radians. If the plane is 60 metres long it is 60/0.05 = 1200m away. Still 1km away but we were at least that distance from the airport itself.
