Operational Lumens Output is the luminous flux delivered by the complete lamp under defined operating conditions. It accounts for optical, electrical, and thermal losses within the finished product and therefore represents real lamp performance more closely than theoretical lumens. Nordic Lights lists operational lumens in its product technical data. This is the appropriate lumen value for comparing the delivered flux of complete lamps when the values are measured under comparable conditions. It still does not describe the shape, intensity, or useful placement of the light. Light pattern, photometric data, mounting position, aiming, and application conditions are also required to assess real visibility.