What Is Sony MotionFlow?by Steve Lander
MotionFlow is Sony's motion compensation system that helps to bridge the gap between the frame rate of recorded material -- movies or TV shows, for example -- and the refresh rate of their screens. While it can make on-screen motion seem much smoother and less blurry, some feel that it gives the image an unrealistic appearance.
Television sets work by constantly displaying a new still picture. The original television specification called for a 30-Hz refresh rate, meaning that it had 30 different images per second, while the original Liquid Crystal Display flat screen sets had a 60-Hz refresh rate. As of the end of 2012, Sony's highest end LCD sets have either 120- or 240-Hz refresh rates.
Most motion pictures are filmed at 24 frames per second, while many video programs are filmed at a rate of 30 frames per second -- although some sporting events get filmed at 60 frames per second. These frame rates are slower than what most Sony TVs can reproduce. MotionFlow technology converts 24 to 60 frame per second to show on a display that operates at 120 or 240 frames per second.
Moving Pictures and Your Eyes
At the movies, even though you see 24 different pictures with a short interval of blankness between them, you perceive them as a constant moving picture. This happens because of a quirk of the human visual system called the "persistence of vision." When you see an image, it remains on your retina for a short period of time after it goes away, letting you see a movie as a solid image. However, your brain still perceives these intermittent images differently than it does a constant image like what you see in the real world or a high-speed image like the one produced by a high refresh rate TV set with MotionFlow.
When you have a film that is filmed at 24 Hz, there are two different ways to put it on a 120-Hz television set. One is to show each frame five times. The other, which is what Sony MotionFlow does, is to create frames that represent averages of the two frames and show them in the intervals between the two original frames. Doing this creates a smoother and more natural appearance. However, because it looks very different from the slightly jittery motion you see at the movies or on traditionally filmed television, some feel that it looks unrealistic, referring to it as the "soap opera effect." If you do not enjoy the appearance of the MotionFlow processing on your Sony TV, you can turn it off.
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