By setting the high range of the sensitivity (Trigger) range you can ignore motion that occurs over a larger area. Example to ignore cars but trigger on people you would decrease the high range. Easiest way to determine the high range in this example is to have a person walk thru the motion detection area and observe the motion graph on the camera view bottom bar (the hi/lo sensitivity range is noted in the bar by green vertical lines) . Then you will know where to set the high range. This would then exclude say a car driving by but not a person walking by (also excluded alerts from large light changes, cloud changes etc. It seems to work best when you setup a motion area rather using the entire carmra motion area.