A mobile radiography apparatus has a portable transport frame and a sectioned vertical column mounted on the frame and defining a vertical axis and having a base section having a fixed vertical position relative to the vertical axis and at least one movable section that is translatable to a variable vertical position along the vertical axis. A counterbalance apparatus is coupled to the at least one movable section of the vertical column with an actuator that is energizable to translate the at least one movable section along the vertical axis. A boom apparatus supports an x-ray source and is coupled to the at least one movable section for vertical displacement of the boom apparatus to a height position. A height sensing element provides a signal that is indicative of the height position of the boom apparatus.