Fig. 4

Calibration setup, viewed from the top. The stand with the calibration target and the vial (red cap) containing the tracer are placed on the left (1). The collimator with the attached camera fixation frame for the microscopic cameras and the LEDs (lighting) are to the right (2). The detector element is adjacent (3). The distance for this measurement is 110 mm from the collimator front plate to the target (calibration default). Not shown is the data processing unit of the detector. A 1-euro coin in the lower left serves as a scale reference