Slow-motion iPhone video footage of the sea integrated with 3D animation — just for fun.
Shot on my iPhone from the top deck of a ferry on it’s way to France, and looking down on the English Channel, Icaptured the footage in slow-motion. A week later when I got back home I downloaded a 3D model of an RAF Sea King rescue helicopter and animated it flying over it.
Calculating the helicopter speed
I wanted the helicopter flight to look as natural as possible in slow-motion so that meant trying to calculate how fast the rotors would be travelling and the speed of the chopper in relation to the slow motion waves of the sea.
I found out that the average helicopter propeller rotates at between 460 and 600 RPM (rotations per minute); the footage was filmed at 100 FPS (frames per second) which is 4 times slower than normal speed footage which is usually 25 FPS; So, I worked that the propeller needed to rotate 15 times (15 x 360° = 5,400°) per second.