optical control factor (illumination) (OCF)

The directionality of LED lighting is limited in that the beam angle of LED spots is wider than that of halogen spots. In order to better evaluate and compare lighting solutions with spot radiation of LED lamps, the company Cree proposed the Optical Control Factor ( OCF), a characteristic value with which the directional beam characteristics of LED lamps can be measured.

The OCF factor is calculated by dividing the luminous flux(lumens) by the scaled area in square millimeters. The scaled area is the light- emitting area of the light-emitting diode. Thus, the OCF factor increases as the luminous flux increases or as the scaled area decreases. For LED arrays, the scaled area increases with the number of LEDs.