A method for training a function of an X-ray system that has a positioning mechanism such as a C-arm, a detector, and, in a beam path in front of the detector, an anti-scatter grid. Positioning of the detector at a large number of different positions occurs. The positioning mechanism is deflected and/or distorted. Recording of at least one X-ray photograph in each of the positions then takes place, and the method further includes machine learning of artifacts generated by the anti-scatter grid from all X-ray photographs for the function.