desdesThe invention relates to an X ray imaging apparatus and a method particularly to a CT scanner (100) for generating sectional images of an object such as the body (P) of a patient. A given desired angular intensity distribution (I) is reproduced by emitting X rays (X) in emission angle intervals (EAI) only wherein the angular distribution of these emission angle intervals and the associated local emission intensities (1(a)) are chosen such that they reproduce in the angular mean the desired angular intensity distribution (I). Modulation of incident X ray flux is hence realized by the modulation of the angular sampling density. The X ray source may preferably be realized by a grid switching tube (101).