Soap Effect

[hawtdawg]

False. Interpolation exists to hide problems in the source material.

24fps is a pretty low framerate. When dealing with fast action or panning there will be judder at 24fps. Most of our lives 3:2 pulldown hid this judder.

With 120hz tvs we could finally watch movies at 24fps as intended but when we did we encountered judder (made worse by LCD's poor motion resolution). TV makers expected to be blamed for this judder (even though the problem is the source) so they created interpolation to stick back in artificially the missing frames that causes judder. As a side effect we got the soap opera look because it interpolates 24fps to 30fps (aka the framerate soap operas use).

I think just about every bit of this is wrong.

Judder is what happens when extra frames have to be inserted due to 60 not being divisible by 24 (ie, 1 out of every 5 frames has to be a repeat). There is no judder with a true 120hz panel. Sure, movies have low framerates, but this is not a "problem" with the source, and 120hz does absolutely nothing whatsoever to harm the picture or add any sort of judder. 120hz did not make anything worse, it removed the judder, because there were no repeat frames. Interpolation "hides" judder on 60hz panels, because that is where the judder happens.

On another note, soap operas, while mathematically being 30fps, had a temporal resolution of 60 unique fields per second. IE each field was from a different moment in time. this is what gave soap operas their smooth look. Interpolation on a 60hz panel takes a 24fps movie and tries to interpolate it to 60fps. This is why it is called the soap opera effect.

Interpolation sells 120hz panels to the laymen. Average joe is going to have no clue why he would need a true 120hz panel, but salesmen can "show" them by turning on the interpolation.