Method of adjusting a registration mapping, the registration mapping combining data indicative of spatial positions in a three-dimensional operating space and image data acquired with an imaging device located in a position and orientation in said three-dimensional operating space referred to as imaging pose, the combination being performed by mapping the spatial positions in the three-dimensional operating space to two-dimensional coordinates of the image data, the registration mapping being determined by means of markers in spatial positions determined by known relative positions to the imaging device imaged with the imaging device in the imaging pose, the method comprising the steps: a) bringing a phantom into a first position and orientation in the three-dimensional operating space, referred to as first pose, where the phantom is at least in partial view of the imaging device located in a second pose, the phantom comprising an assembly of the markers in the known relative positions to the imaging device that can be imaged by the imaging device; b) acquiring image data of the marker assembly of the phantom with the imaging device in the second pose; c) locating imaged markers in the acquired image data of the marker assembly using image analysis, thereby finding imaged marker positions; d) obtaining mapped marker positions by applying the registration mapping to spatial positions of the markers in the marker assembly of the phantom in the first pose using the second pose or, in case a different pose has been determined in step g), the different pose as imaging pose; e) determining a distance measure between the imaged marker positions and the mapped marker positions as the measure of accuracy of the registration mapping; characterized in that the method comprises f) performing steps g), d) and e) until two consecutive measures of accuracy of different poses obtained in step g) approach one another up to a predetermined threshold or until a predetermined convergence criterion is met, and, in case the two consecutive measures of accuracy of the different poses obtained in step g) approach one another up to the predetermined threshold or in case the predetermined convergence criterion is met, continuing with step h); g) virtually transforming the imaging pose used in the registration mapping to a different pose; and h) outputting the registration mapping as a result. a) bringing a phantom into a first position and orientation in the three-dimensional operating space, referred to as first pose, where the phantom is at least in partial view of the imaging device located in a second pose, the phantom comprising an assembly of the markers in the known relative positions to the imaging device that can be imaged by the imaging device; b) acquiring image data of the marker assembly of the phantom with the imaging device in the second pose; c) locating imaged markers in the acquired image data of the marker assembly using image analysis, thereby finding imaged marker positions; d) obtaining mapped marker positions by applying the registration mapping to spatial positions of the markers in the marker assembly of the phantom in the first pose using the second pose or, in case a different pose has been determined in step g), the different pose as imaging pose; e) determining a distance measure between the imaged marker positions and the mapped marker positions as the measure of accuracy of the registration mapping; characterized in that the method comprises f) performing steps g), d) and e) until two consecutive measures of accuracy of different poses obtained in step g) approach one another up to a predetermined threshold or until a predetermined convergence criterion is met, and, in case the two consecutive measures of accuracy of the different poses obtained in step g) approach one another up to the predetermined threshold or in case the predetermined convergence criterion is met, continuing with step h); g) virtually transforming the imaging pose used in the registration mapping to a different pose; and h) outputting the registration mapping as a result.