Stereo ranging systems having pairs of imaging devices may be calibrated by projecting beams of light into the fields of view of the imaging devices and comparing the appearances of reflections of the beams depicted within images captured thereby. Where the reflections appear consistently within the images, the stereo ranging systems may be determined to be calibrated and operating properly. Where the reflections do not appear consistently within the images, the stereo ranging systems may be determined to be not calibrated or not operating properly. The light sources may be light-emitting structures such as diodes or reflective objects. A vector generated based on inconsistencies in appearances of reflections within images may be used to adjust the images. Images adjusted based on such vectors may be used to determine ranges to objects depicted therein or for any other purpose.