... of the traditional medical film observation lamp. And the entire screen of the observation lamp is more brighter, uniform and ... :Light source and color temperature:≥6500kBrightness in the center of screen: ≥2000cd/m2, 3000 and 4000 cd/m2(6500Lux, 9750Lux, ... 7Stability of the screen surface brightness: less than 2%Light source frequency : 50000Hz.rating life of LED: 100,000h. LED Negatoscope (single ...