1. A movable X-ray imaging system for aligning an object of interest and an X-ray imaging arrangement in relation to each other, the system comprising: an X-ray imaging arrangement with an X-ray source and an X-ray detector; at least one camera; a data processor; and a display; wherein the at least one camera i) is either attached to the X-ray imaging arrangement or ii) is attachable to the object of interest; wherein the at least one camera is configured to provide a first image of at least one reference point; wherein the data processor is configured to relate the first image to first projection parameters of a first X-ray image of the object of interest in relation to the object; wherein the projection parameters relate to different degrees of freedom and comprise at least one of the group of spatial projection position, distance to the object, viewing direction or projection angle, and viewing field; and wherein, for an acquisition of at least one further X-ray image in a projection coincident with the first projection parameters of the first X-ray image, the display is configured to display at least a graphical representation of the at least one reference point in the first image at least partly overlaid with an actual image provided by the at least one camera to guide an alignment movement of the X-ray source and/or the X-ray detector and the object in relation to each other after an intermediate displacement.