An apparatus (130) and method for automatically or semi-automatically controlling a collimator (COL) of an x-ray imager (100) to collimate imager (100)'s x-ray beam and adjusting an alignment of the x-ray imager (100) in respect of an object (PAT). The collimation and alignment operation is based on 3D image data (3DI) of the object (PAT) to be imaged. The 3D image data (3DI) is acquired by a sensor (S). The sensor (S) operates on non-ionizing radiation. The 3D image data (3DI) describes a shape in 3D of the object (PAT) and anatomic landmarks are derived therefrom to define a collimation window (W) for a region of interest (ROI). Based on the collimation window (W) the collimator (COL)'s setting and imager (100) alignment is adjusted accordingly.
