A lithographic apparatus includes a patterning device support to support a patterning device, the patterning device system including a moveable structure movably arranged relative to an object, a patterning device holder movably arranged relative to the movable structure to hold the patterning device, an actuator to move the movable structure relative to the object, and an ultra short stroke actuator to move the patterning device holder with respect to the movable structure; a substrate support to hold a substrate; a projection system to project a patterned radiation beam onto a target portion of the substrate; a transmission image sensor for measuring a position of the patterned radiation beam downstream of the projection system; and a calibrator for determining a relationship between magnitude of an applied control signal to the ultra short stroke actuator and resulting change in position of the patterned radiation beam and/or patterning device holder and/or patterning device.