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Published: 2012-08-02 - 12:44:02
Home Theater : Ask The Expert

Why Do Some TVs Make Movies Look More Real than Others

By Chris Boylan

Dear Big Picture Big Sound,

I am thinking of buying an HDTV and notice that at the stores some TVs make the movies look more real life than having the movie lighting etc. I like it, what feature would I look for to make sure my tv can do this?

-Chris A.


Hello, Chris,

The topic is one of considerable debate among home theater and video aficionados and hobbyists.  In North America, movies are normally shot at 24 frames/second while video is typically shot and displayed at 60 frames/second.  Televisions display most content - video or film - at 60 Hz (60 frames/second).  This means that the native film material has to be manipulated to be displayed at 60 Hz.  This process, known as 3:2 pulldown processing, introduces something called "judder."  Judder is a slight jerkiness in motion that occurs when you map film-based content (24 frames/second) to a video display (60 frames/second).  Since it can't be mapped evenly from 24 to 60, you get some extra frames introduced which can make the motion a little choppy.

But as TVs have evolved with higher frame rates than 60 Hz (120 Hz, 240 Hz or even higher), TV manufacturers have developed methods of making the on-screen motion smoother than the original film or video source.  This feature or technique is called motion interpolation, as the video processor creates intermediate images between frames by interpolating or estimating the difference between each original frame in the video signal.

Samsung Auto Motion Plus 240
Motion interpolation, such as Samsung's Auto Motion Plus 240, add intermediate frames between the real frames to make motion appear smoother (image courtesy of Samsung).

Different manufacturers have different names for their versions of motion interpolation.  You may hear it called motion smoothing; IFC - Intelligent Frame Creation (Panasonic); MEMC - Motion Estimation, Motion Compensation (VIZIO); TruMotion (LG), Auto Motion Plus (Samsung), AquoMotion (Sharp) or MotionFlow (Sony).  The various implementations of motion interpolation may look better or worse depending on how good the processing is, but in general all of these will impart movies and TV programs with smoother motion.

As to whether motion interpolation makes a movie look "better," that's where the debate comes in.  Some viewers, including yours truly, prefer to see movies at their native frame rate (24 Hz) with no interpolation.  This preserves the original intent of the director, who shot the film knowing that it would be projected in theaters at a multiple of 24 Hz.  The reason it has to be a multiple of 24 Hz is that projecting the film at exactly 24 Hz would cause so much flicker as to be unwatchable.  The film projectors in movie theaters usually display films at 2X (48 Hz) or 3X (72 Hz) speeds.  Some higher end TVs (such as Samsung and Panasonic plasmas and high end LED/LCD models) offer a native 24p frame rate option for viewing films.  These duplicate the original 24p frames at a multiple of 24 Hz (48, 72 or 96) with no motion interpolation, thereby preserving the "cinematic" look.

But that said, many viewers do prefer the look of a film with motion interpolation applied.  So if that's what you like, then look for motion interpolation under one of the above names.  Or better yet, get a high end Samsung or Panasonic which offers both motion interpolation and a native 24p mode so you can try both and see which you prefer.

Hope that helps.

-Chris

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