A system and method for accurately determining the positioning of a lens system. The lens system includes a lens and a mono-color light reflecting surface. A position sensor includes a light source and a light detector. An initial signal is sent from the light source to the monor-color light reflecting surface. The light reflecting surface reflects the initial signal to the light detector at a reflection region. The intensity of the reflected signal is dependent upon the distance between the reflection region and the position sensor, which is variable. An electrical output signal is generated based upon the reflected signal from the light source, with the electrical output signal providing positioning information for the lens system.