The invention relates to an operating method for an imaging system for the time-resolved mapping of an iteratively moving examination object. First recordings of the object are generated by the imaging system from various angles while simultaneously recording a phase signal. Multiple static 3D-image data sets corresponding to a sequence of defined phases are reconstructed from the first recordings. Three-dimensional motion fields are calculated from the 3D-image data sets, by which two 3D-image data sets are mapped onto one another. Second recordings of the object are generated by the imaging system from various angles while simultaneously recording a phase signal. 3D-image data sets from the second recordings in a previously determined reference phase of the phase signal using the motion fields is generated which is a sequence of motion-compensated 3D-image data sets.