He leido esto en un foro americano y deja todo bastante claro:
"Since no one seems to be giving the foundation details, it might help to really understand what "24" is and why it is even a discussion.
To start with, you have to know that all movies are filmed at 24 frames per second. (the numbers are actually 24 * 1000/1001, but let's keep this simple...) When they show a movie in the theater, flashing 24 frames per second will result in an incredible flicker on the screen. So they use essentially a shutter that flashes at 3 times the rate of the film, ie 72 times per second. That get's rid of any flicker. The problem comes when you try to transfer that movie over to TV media. For the longest time, with DVD, the film was transfered using 3:2 pull down onto the DVD.
3:2 (or 2:3 which ever you prefer) is a process of unequally displaying frames to arrive at an even 60 frames per second. The process shows the first frame 3 times, the second twice, then 3, then 2, etc... like this:
AAA-BB-CCC-DD-EEE-FF-GGG.....
When you add them all up, you get 60 frames instead of 24. However, as is the case with any kind of forced processing, some unnatural results can occur. The term "judder" was used to explain the results of the 3:2 pull down. Since PQ is subjective, some people complain more about judder than others. Cnet defines judder as:
A visual artifact that often occurs when film is transferred to video. The result is what appears to be jerky or stuttering camera movement, where it should be a smooth pan.
So, what if you could replicate the same FPS as a movie? what if you could avoid 3:2 pull down altogether? Enter,
BD and 24p. The problem is, not many TV's are really capable of true 24p rendition. Some say they can, but in truth, they just do a 3:2 pull down internally which ends up with the same result as before.
Pioneer is a good example, though not the only TV that does it right. Pioneer, instead of forcing 3:2 pull down, actually changes the refresh rate of the TV from 60Hz (standard for most TV's) to 72Hz. The result is 3:3 (or the same as a movie theater). Judder is gone and all the other issues with 3:2 pull down.
So what about 120Hz tv's? if you did the math, you noticed that 120 is a multiple of both 60 (X 2) and 24 (X 5). Result, no 3:2 pull down.
So where is it appropriate? Any time you watch a movie on
BD as they are all mastered at 1080p/24Hz. Will you notice it? If you don't have a problem with DVD's, you might not since you've been watching 3:2 all along. But, if you see it (I do) then you will care."