Tricks of motion
Wagon-wheel effect
How fast is the propeller turning?
Very fast, though in the video it seems to turn slowly, or even bend. In old films, wagon wheels often seem to turn backward.
Why? A camera takes a fixed number of pictures a second. If the blade turns almost a whole turn between pictures, it looks like it has barely moved.
Picture: Silverchemist, CC0 · Wikipedia(opens in a new tab)