1. A method of controlling a camera using a distance of two objects in a 3D monitored space, the method including: identifying from images captured by the camera first and second objects present in the 3D monitored space, the first and second objects at least partially within a field of view of the camera; repeatedly calculating spatial coordinates of the first and second objects present in the 3D monitored space based upon the images captured by the camera and calculating a distance between the first and second objects in space from the spatial coordinates; and responsive to the calculated distance, adjusting a camera parameter; whereby the camera is enabled to capture additional images of the first and second objects moving in space relative to the camera.