1. An object illumination and image capture system part of a person-machine interface comprising: a camera having a fixed field of view; a plurality of individually controllable lighting elements directed toward the field of view, at least some of the lighting elements having different beam angles, including at least one wide-beam lighting element and one or more narrow-beam lighting elements; and a controller coupled to the camera and the light sources and configured to: operate the camera to capture a sequence of images including a control object arriving at and moving in the field of view; operate the lighting elements to illuminate the field of view with the wide-beam lighting element while detecting the arrival of the control object and to activate the narrow-beam lighting elements and follow the control object with the narrow-beam lighting elements as it moves within the field of view; and illuminate the moving control object using the narrow-beam lighting elements with sufficient intensity to facilitate detection of control gestures by the control object within the field of view.