A radiographic image is obtained by combining at least two radiographic sub-images acquired by at least an upper and lower 2-dimensional radiation sensor having sensor pixels. The radiation sensitive area of the lower sensor is overlapped by the upper sensor. Overlap is preferably at least two pixel rows, but can also be limited to non-imaging parts of the upper sensor. The radiation sensors may comprise a radiation to light converting layer.Preferably the sensors are built using CMOS technology, exhibiting less radiation absorption outside the radiation sensitive area.