Abstract: An x-ray imaging system includes an x-ray source assembly having a transmitter and a video camera. A free standing digital radiographic (DR) detector includes a receiver, wherein the transmitter and receiver are configured to determine an spatial orientation of the digital radiographic detector relative to the x-ray source assembly. A digital display presents a live video image of a patient with a current position of the DR detector overlayed on the video image of the patient. A DR detector having built-in AEC sensors may display the current position of each of the AEC sensors in the overlay relative to the DR detector position based on the determined orientation of the DR detector. Each of the AEC sensors are individually activatable, and an AEC selection interface is configured to receive an operator selection of one or more of the AEC sensors to be activated.