"But you are right that Collateral did do something very new/unusual at the time, and that was shooting scenes in higher frame-rates than 24, and mixing multiple frame rates in a film. (This might not sound like much, but until this time, pretty much every film was 24fps for the previous eighty years and it had a very specific look that everyone's eyes/brains were conditioned for, unbeknownst to them.)"
Why was certain scenes in Collateral filmed in other frame rates than 24 fps (unless you are doing slow motion of course)? AFAIK it was never projected/shown in anything else than 24 fps.
Correct, theaters at the time could not really been project anything other than 24fps. So there were 2 parts to the shooting style, and one of them is what you describe, shooting at the higher frame rate used in order to have it play back slower when conformed to 24. But they did this in a pretty unusual way. During the action sequences, they would ramp up frame rate from 24 to 30 and back down. They would do adjust during the shot, so the action scenes had these subtle but constantly-occurring increases and decreases in speed that looked very interesting and had not been done before.
The other major part was the shutter speed. They of course could not actually shoot/project 48/60fps, but they a shot a lot scenes at the high shutter speeds one typically uses when shooting those frame rates, a lot of it had that "ultratrealistic" look that people had weren't used to in films, resembling more the look of video, TV soap operas in 60i, etc.
I feel slightly absurd even writing about this considering how little of this really applies today, and how inconsequential changing the shutter speed on a camera is now. "I hit the '+ shutter' button a couple of times, revolutionary!" But it's crazy how conditioned everyone was to these looks at the time due to how little variety there was. I taught this film class where I would demonstrate to everyone, with nearly 100% success, that they all were influenced by and conditioned for these frame rates, even if they didn't know what a frame rate was. We'd shoot a scene with multiple cameras side-by-side shooting at different frames rates, play it back to the class later, and ask which one looked "more like a movie" to them. Invariably, even if they couldn't explain why, everyone always picked the 24p version
"Correct, theaters at the time could not really been project anything other than 24fps. So there were 2 parts to the shooting style, and one of them is what you describe, shooting at the higher frame rate used in order to have it play back slower when conformed to 24. But they did this in a pretty unusual way. During the action sequences, they would ramp up frame rate from 24 to 30 and back down. They would do adjust during the shot, so the action scenes had these subtle but constantly-occurring increases and decreases in speed that looked very interesting and had not been done before."
Wouldn't this just lead to judder? Maybe that was something that had not been seen before in a movie shown at cinemas.
I've heard that sometimes scenes like kung fu fights were filmed in a lower frame rate (maybe 20 fps) and then it got faster when it was projected in 24 fps. If you do it the other way around movement just get slower (which is what you want for slow motion).
"We'd shoot a scene with multiple cameras side-by-side shooting at different frames rates, play it back to the class later, and ask which one looked "more like a movie" to them. Invariably, even if they couldn't explain why, everyone always picked the 24p version"
Isn't this the most expected result? How could it possibly be anything else?
At the time, yes, absolutely, and that's why I did it. It was a lesson that everyone understood intuitively the moment the saw the comparison, even if 30 seconds prior to that they thought it was nonsense, or didn't really have thoughts one way or the other because they never given much thought to frame rates before.
But would this experiment yield the same results today? For people in certain demographics or below a certain age, I think almost certainly not.
I also think that a lot of the people who would've easily identified the 24p clip back in 2004ish when this class took place may no longer do so now. I never would've thought this before 2018ish, but I had experiences with people around and since that time that surprised me and turned me completely around on this view.
Though there is one other alternative that that I wouldn't have difficulty believing. I think it's possible that more people than I just predicted would identify the 24p clip as "cinematic", but that they may not view it as a desirable look, inherently more dramatic, having much impact on the viewer, etc.
In the book _In the Blink of an Eye_ by Walter Murch (which is generally about film editing), there's a section that speculates that 24 frames per second somehow resonates with some innate constant of how human vision works, which is wild to think about!
I remember exactly when I learned that, and indeed I found it interesting and thought-provoking at the time. And it's still interesting now, but I personally think it's way less likely true than I did back then