Against the strict definition of "detecting motion", the motion detection function is essentially observing changes over a set duration, for the configured percentage of the scene as defined in the camera settings. If set to the maximum value of 100% sensitivity, then very small changes in scene at a longer range (and likely higher counts of false positives) will be logged as motion events.  Looking at motion detection for specifically vehicles or people however (i.e. object detection), the answer is contextual to the camera settings and the environment it is deployed within. Factors like pixels-per-foot and the resolution and quality settings affect these detections.  Starting with our third generation cameras, our product teams are releasing DORI specifications at maximum resolution (see the MV73 datasheet) to help in identifying the maximum expected range permissible for distinct recognition between objects. For second generation cameras, I would suggest testing with your desired quality settings to be able to find the largest achievable range for reliable detection. ... View more