Abstract: This invention provides a system and method for automatic runtime determination of calibration and alignment of multiple cameras in a cross surface inspection arrangement. A plurality of flags each move into and out of a field of view of each of the cameras. These flags actuate at predetermined times. When actuated, the flags present a known geometric shape to the region of interest, which can be used to determine whether a camera has drifted in calibration or alignment with respect to a previously calibrated, trained image of the flags. The flags can be mounted on rotary actuators that are placed at predetermined intervals along an illumination bar. The illumination bar can be located on a side of a moving web opposite a side facing the cameras. The illumination bar projects a light line through the translucent web that is momentarily interrupted at periodic intervals by the actuated flags. In operation, the cameras operate a runtime inspection process.