1. A method of navigating a trajectory by a robotic apparatus comprising a controller, an actuator and a sensor, the method comprising: obtaining at least one image associated with surroundings of the apparatus using the sensor, the sensor comprising two or more discrete image detectors, each of the two or more discrete image detectors sharing a common lens and being associated with respective two or more areas of focus, the two or more areas of focus corresponding to two or more respective extents in the surroundings; analyzing the at least one image to determine a contrast parameter of the at least one image; detecting a presence of an object in the at least one image based at least in part on the contrast parameter meeting one or more criteria; during the navigating of the trajectory by the robotic apparatus, determining a distance to the object when the presence of the object produces an in-focus representation within a given extent of the two or more extents in the surroundings; and causing the controller to activate the actuator based on the detection of the presence of the object; wherein the actuator activation is configured consistent with a characteristic of the object.