1 - Method of servoing an X-ray source ( 800 ) in a radiography device comprising a MOS-type image sensor ( 810 ) with pixels ( 10 ) provided with separate read ( 30 ) and refreshment ( 20 ) controls, respectively, in which, during a radiography operation, read controls of a plurality of image sensor pixels are called repeatedly, while maintaining a source of X-rays power supplied, so as to establish, in response to each reading, at least one image acquisition characteristic, and in which the emission of X-rays is interrupted when the image acquisition characteristic corresponds to a preset image acquisition characteristic.