Abstract: Use of an optical element (1) in an optical measuring system, and such a measurement system, with a camera, whereby this optical element (1) contains a light source (2) with an active side (4) which lights up when an electric tension is applied via electric contacts (9,13) provided to this end, whereby this light source is mounted against a translucent wall (3), such that the light of the active side (4) can be seen through this wall (3), and whereby this translucent wall (3) is formed of transparent fibers (5) placed side by side in a parallel manner.

Abstract: A method for measuring the displacement of a vehicle wheel relative to the frame thereof or relative to a fixed point of reference. The vehicle is located on a test stand in which the wheel is loaded, statically or dynamically. In a first step, a measuring system including cameras measures the position of at least three points of reference on the wheel, these three points of reference not being in a straight line. In a second step, the relative displacement of the wheel is calculated.