100 Hz MotionFlow in LCDs: What Exactly Is It?

The HDTV market, dominated by swanky LCDs, has been steadily growing, and for a country as dynamic as ours, the end is nowhere near. But, how does one get attracted to a particular model? What piques our interest? The answer lies in the obvious: the features. Even before the review, we look at the features. One such feature that took the LCD world by storm back in 2005-06 was the Motion Compensation option, introduced in the video processing circuit. Its also known as 100 Hz Flicker free technology.  

 

image courtesy: Behardware 

The theory is quite simple: In India, we originally  receive broadcasts of the PAL B/G kind, which consists of 625 lines, at the frame rate of 25 frames per second. Out of these 625, there are 576 active lines that make up the video. Also this signal is interlaced, meaning one frame of video that we see, is made up of 2 successive fields. These 2 fields contain alternate lines, which when played together fast, one after the other, result in one homogeneous frame. Thus the TV has to deal with 50 fields of info coming to it every second, or 50 Hz Refresh Rate. 

Now comes the human eye, and our perception of vision. Shake your hand very fast in front of your face. you will see a blur, and not really see the edges of your hand. But still there is no real proof that the human eye sees only 15 or 30 frames per second. We live in an infinite, analog world if I may say so, nature in its essence is analog. Thus we cannot put an exact number on how many frames per second our eyes can see; in some test cases results have said to exceed 100 frames per second. 

 

  image courtesy: Behardware  

 

Thus obviously, when we see something fast moving, like sports broadcasts in 50 Hz, chances are we'll see a blur in moving images, like 3 balls instead of 1 or afterglow in the images. Samsung and Sony get some credit for being involved in the first generation of Motion Compensation features, where it was called 100 Hz Motion plus. This algorithm processes the incoming video signal. It basically interpolates a frame in between 2 received ones, resulting in one artificially created, new frame sitting in between 2 originals. This aims to make the overall motion look smoother, and theoretically it should. There are calculations involved in this, thus these models are more expensive; in fact 2 absolutely similar LCDs, with just 100 Hz motion feature being the difference, will have a 10K price difference.