Comment by BeFlatXIII 3 hours ago
I suspect 24fps is popular because it forces the videography to be more intentional with motion. Too blurry, and it becomes incomprehensible. That, and everything staying sharp at 60fps makes it look like TikTok slop.
I think the "real" problem is not matching shutter speed to frame rate. With 24fps you have to make a strong choice - either the shutter speed is 1/24s or 1/48s, or any panning movement is going to look like absolute garbage. But, with 60+fps, even if your shutter speed is incredible fast, motion will still look decent, because there's enough frames being shown that the motion isn't jerky - it looks unnatural, just harder to put your finger on why (whereas 24fps at 1/1000s looks unnatural for obvious reasons - the entire picture jerks when you're panning).
The solution is 60fps at 1/60s. Panning looks pretty natural again, as does most other motion, and you get clarity for fast-moving objects. You can play around with different framerates, but imo anything more than 1/120s (180 degree shutter in film speak) will start severely degrading the watch experience.
I've been doing a good bit of filming of cars at autocross and road course circuits the past two years, and I've received a number of compliments on the smoothness and clarity of the footage - "how does that video out of your dslr [note: it's a Lumix G9 mirrorless] look so good" is a common one. The answer is 60fps, 1/60s shutter, and lots of in-body and in-lens stabilization so my by-hand tracking shots aren't wildly swinging around. At 24/25/30fps everything either degrades into a blurry mess, or is too choppy to be enjoyable, but at 60fps and 1/500s or 1/1000s, it looks like a (crappy) video game.
Is getting something like this wrong why e.g. The Hobbit looked so damn weird? I didn't have a strong opinion on higher FPS films, and was even kinda excited about it, until I watched that in theaters. Not only did it have (to me, just a tiny bit of) the oft-complained-about "soap opera" effect due to the association of higher frame rates with cheap shot-on-video content—the main problem was that any time a character was moving it felt wrong, like a manually-cranked silent film playing back at inconsistent speeds. Often it looked like characters were moving at speed-walking rates when their affect and gait were calm and casual. Totally bizarre and ruined any amount of enjoyment I may have gotten out of it (other quality issues aside). That's not something I've noticed in other higher FPS content (the "soap opera" effect, yes; things looking subtly sped-up or slowed-down, no).
[EDIT] I mean, IIRC that was 48fps, not 60, so you'd think they'd get the shutter timing right, but man, something was wrong with it.
24fps looks a little different on a real film projector than on nearly all home screens, too. There's a little time between each frame when a full-frame black is projected (the light is blocked, that is) as the film advances (else you'd get a horrid and probably nausea-inducing smear as the film moved). This (oddly enough!) has the effect of apparently smoothing motion—though "motion smoothing" settings on e.g. modern TVs don't match that effect, unfortunately, but looks like something else entirely (which one may or may not find intolerably awful).
Some of your fancier, brighter (because you lose some apparent brightness by cutting the light for fractions of a second) home digital projectors can convincingly mimic the effect, but otherwise, you'll never quite get things like 24fps panning judder down to imperceptible levels, like a real film projector can.