Black Frame Insertion (BFI)
One of the benefits of the faster response time is the ability to incorporate what is called black frame insertion. By inserting a black frame in between the normal video frames, not only does the overall response of the pixel improve because the gray to black and back to gray will occur faster than gray-gray transitions in these fast LCDs, but the inserted black frames between the picture frames allows for improved black levels approaching those available with a CRT. So right there you can see the value of a 8 ms LCD since the frames will be doubled requiring a 120 Hz screen update. On some slower responding LCDs this black frame is inserted by turning off the backlight rather than just the LCD pixels.