A method is disclosed for reconstruction of image data of an object under examination from measurement data, with the measurement data having been recorded during a rotating movement of a radiation source of a computed tomography system around the object under examination. A linearized signal can control, for example, a microelectromechanical device, a microelectromechanical device, andor a device controlling a modulated intensity of electromagnetic energy. The paths are configured such that during the stretching an extent of uniaxial character, U, is between zero and unity and a minimum value of an extent of uniaxial character, U, is at least 0. The first end of the first member has flanges extending laterally and the second end of the first member has flanges extending laterally such that the first member is substantially H-shaped in cross-section. Two eccentric bushes are rotatably fitted over the eccentric cams. Alternatively, a travelling wave can be created over the whole area of the mark so that echoes off the top and bottom of the buried mark carry positive and negative images of the mark; these cause reflectivity differences and displacements when they reach the surface which can be aligned to.