A method of sensing a component held by a nozzle of a pick and place machine is provided. The method includes engaging a source of illumination and recording a reference background image when no component is held by the nozzle. Then, a component is adhered to the nozzle. A shadow image of the component is detected while the component is held by the nozzle. The detected shadow image of the component is adjusted based upon the recorded reference background image. Positional information relative to the component held on the nozzle is computed using the adjusted shadow image. The component is then mounted upon a workpiece using the positional information.