Abstract: A device and a method for determining the quality of imaging of printing plates by means of, in particular, an optoelectronic sensor for detecting a reference mark that is disposed inside or outside the printing area which includes different reference fields is provided. An evaluation unit is provided for evaluating the measured values determined by the sensor. The sensor is configured to detect at least two reference marks located on the printing plate. Each of the reference marks includes a combination of reference fields having at least one tone value reference field and at least one structured reference field, or at least one reference mark includes at least one tone value reference field while at least one additional reference mark includes at least one structured reference field.