Quote:
Originally Posted by
Joe Bloggs 
They probably sacrificed a little bit of real motion blur.
That can mean two different things. Here's how I would explain it.
1. At 48fps,
A. With panning, there won't be any or much motion judder.
B. With fast moving objects, there won't be as much motion blur per recorded frame.
Now here's the tricky part I was thinking about.
2. At 24fps.
24fps is half of 48fps. So to get real classic theatrical motion picture action from something originally recorded at 48fps, only half of the frames are needed. BUT, does that give us the same effect as something originally shot at 24fps?
My initial thought was "Yes." But now I've thought about it a bit more, each frame that's recorded at the rate of 48fps is exposed for less time than frames recorded at the slower rate of 24fps.
So here's whats going on.
At 24fps, a really fast moving object going across a recorded frame can't be completely "frozen." So there's going to be some blur to that movement.
At 48fps, that same fast object moving across a recorded frame also cannot be seen as completely "frozen." There's going to be some blur to that movement, but not as much.
At 18fps, (a format used on Super 8 film,) that same fast moving object going across a recorded frame will have even more blur per frame when compared to faster recording speeds such as 24fps and 48fps.
As movie theatre goers, we are accustom to a certain amount of blurring effects during panning and with fast objects moving across the screen. Using half of the frames that originally was recorded at 48fps, may not give us the exact same effect that we're used to when compared to something originally shot at 24fps.
Another words, the effect of using half of something recorded originally at 48fps may look a little "un-cinema" like during pans and fast movement.
I think an experiment could easily show the effects of using higher frame rates for traditional movie displays of 24fps.
Set up two motion picture cameras to record the exact same action at the same time. One would be set to record at 24fps, and the other set to record at 240fps. Make the recording of fast moving objects such as people running, cars driving by, objects thrown across the field of view etc.
Play back the movement originally shot at 24fps. THEN directly compare that with the movement that was shot at 240fps, but with only 1/10 of those frames.
Of course the playback speed on both would be correct, however there will be something very funny looking with the playback of the one originally shot at 240fps.
Edited by Thebarnman - 1/5/13 at 2:07pm