Eliminating fluorescent tubes also allows Sony to increase contrast by dividing the screen into blocks, each lit by a cluster of LEDs. So, for instance, the XBR8 can turn off a part of the screen showing a black car and crank the brightness up for a screen segment that depicts a blazing sun.
Three-color LED backlighting and segmented backlights have both been used before, but never in the same TV, because the quality of LEDs is inconsistent. Say the image of a white car stretches across several segments of the screen. All three colors must light up to make white, but if the brightness of the red LEDs varies, for example, the car will break into a checkerboard of tinted squares—some pinkish, where the red LEDs are too powerful, others greenish or bluish where red LEDs are weaker. To prevent that, Sony workers test and handpick LEDs to ensure similar color among neighboring screen segments.