This video ("rotor panorama") was captured by a camera attached to the rotor head of a radio-controlled helicopter, with the frame rate set to the rotor's frequency. During a long segment of the video, the horizon looks distorted:
What causes this distortion?
This is most likely caused by wobble in the motion of the rotor, compounded with the fact that pixels are captured linearly, probably from left to right (this is what the description refers to as "scanning shutter"). Thus there is a time delay between the capture of the pixels on the left and those on the right; if the axis is not horizontal then this would lead to a vertical displacement between them.
The frame rate and the rotor frequency do not exactly match.the picture seems to be clear some times when the rotor reaches its set rpm. But after that the vibration starts with a different noise.the wobble increases and the distortion too.as Emilio pisanty said there is a vertical displacement due to vibration.
