1. A method of servoing an X-ray source ( 800 ) in a radiography device comprising: calling repeatedly during a radiography operation, read controls of a plurality of image sensor pixels provided via a MOS-type image sensor ( 810 ) with pixels ( 10 ) with separate read ( 30 ) and refreshment ( 20 ) controls, respectively; maintaining a source of X-rays power supplied, to establish, in response to each reading, at least one image acquisition characteristic; and interrupting the emission of X-rays upon the image acquisition characteristic corresponding to a preset image acquisition characteristic.