To test the range of my new 10 mW video tx/rx I try to fly as high as possible without video interferences.
To measure the altitute I record the ground. The FlyCamOne2 has a horizontal view angle close to 60 degrees. So the the distance between left and right border of the picture is about the same as the distance to the ground.
Video tx/rx and voltage converter are from immersionsflug.de