Answer:
It is imperative that the collision takes place in a plane parallel to the plane containing the camera lens so that parallax does not affects the recording of camera.
Explanation:
It is imperative that the collision takes place in a plane parallel to the plane containing the camera lens so that parallax does not affect the recording of the camera. There may occur an error in video analysis if the camera is tilted at an angle in relation to the collision plane.
(The role of the lens is to take light to a fixed focal point.)