A system and method are provided for determining a light output of a light emitting diode (LED) in a scanner. The system includes a processor circuit to execute current control logic to obtain an optimum light output from the LED. The current control logic repeatedly applies increasing or decreasing currents to the LED until a saturation point is identified. This may be accomplished, for example, by comparing two measures of the light output of the LED for two different currents applied to the LED. When a difference equaling a predetermined threshold between the two measures is detected, then the saturation point is identified.