The invention relates to a method for the determination of local deviations of a main magnetic field of a magnetic resonance device from a setpoint value, comprising: loading of a first image data record of an examination region recorded by means of the magnetic resonance device with a first frequency encoding gradient; loading of a second image data record of the same examination region recorded by means of the magnetic resonance device with a second frequency encoding gradient, with the first and the second frequency encoding gradient being different; reception of a transformation displacement field as the end result of a recording of the first and the second image data record; calculation of local deviations of the main magnetic field from a setpoint value on the basis of the calculated transformation displacement field; and display or storage of the calculated local deviations of the main magnetic field.