The framerate conundrum

▼ These days, most of us have devices that can shoot video. And that's no longer as simple as it was 25 years ago. Back then, if you lived in a "60 Hz" country such as the US, your video camera would shoot 30/60 frames per second. (See interlaced video on Wikipedia to understand why this is "30/60".) In parts of the world where the electrical grid runs at 50 Hz, such as Europe, our video cameras would use 25/50 Hz.

Because converting 24 frames per second film to 25 frames per second video is horrible (the image stutters once a second), in 50 Hz territories, film would be sped up to 25 FPS to show on TV or record on video tape or DVD.

But today we mostly just watch Youtube where the video framerate can be 24, 25, 30, 50 or 60 FPS.

Most of us also have a video recording device in our pockets that usually supports at least several different framerates.

So... what's the best framerate?

Film runs at 24 FPS, and many claim that this looks "cinematic". If by "cinematic" you mean "highly compromised", then sure. 24 FPS is barely enough to make movement look natural, so directors of photography working on movies have to be extremely careful about their camera movements. However, they do pay attention to things like the shutter angle. (Which most of us would call "shutter time".)

As computer software all comes from the US, webcams almost always run at 30 FPS and monitors almost always run at 60 FPS.

As webcams don't have the best light gathering ability, they usually push the shutter time to the limit imposed by the video framerate. So at 30 FPS, the shutter time would be 1/30. Or, in Hollywood terms, 360 degrees. This makes all the motion look very blurry and unnatural. Fortunately, talking heads (as we mostly encounter in videoconferences) don't move that much, although hand gestures may.

So...

What is the best framerate to shoot video?

(Also read up about the best shutter speed when shooting video.)

Well, 24 FPS looks "cinematic", for better or worse. 30 FPS is both very common and very compatible with 60 FPS displays as this is a simple framerate doubling. 25 FPS works well in the 50 FPS / PAL world. But these are all quite low framerates. 60 FPS makes a lot more sense to me, or 50 Hz if you want to maintain compatibility with the PAL TV world. So if you want to be on TV. That's probably not goign to happen for most of us, so I'd say that in general, 60 FPS is better than 50, as most of our computer monitors and phone displays run at 60 Hz.

Ideally, you'd want to use 60 FPS because it's a nice high framerate that makes movement look natural. Or 50 FPS if you need compatibility with the 50 FPS world, such as TV broadcasting in 50 Hz countries. But 50 or 60 Hz (at the desired resolutions) may not be supported by your devices.

I'd say avoid 24 FPS unless you need to be compatible with the 24 FPS world. (For instance, if you talk about movies and want to inlcude 24 FPS movie clips.) The reason is that 24 FPS looks terrible when converted to 25 or 50 FPS.

25 FPS is pretty much the same as 24 FPS except that it works without trouble in the 50 Hz world.

But I'd say if 50 or 60 FPS are not possible, and compatibility with the 24 or 25 FPS worlds are not super important, use 30 Hz. It converts to 60 Hz very nicely and to 50 Hz without too much trouble. It's also the native framerate of many devices such as webcams, and 30 FPS over 24 FPS is a 25% higher framerate so a 25% reduction in motion artifacts.

But the most important thing is to avoid having to convert between 24, 25 and 30 FPS as that just looks terrible. Especially 24 ↔︎ 25, and 24 to 50 FPS is also highly problematic.

What, not "cinematic" enough? I don't care. For some reason many people subscribe to "worse is better". Smoother motion isn't worse, it's better. So 60 FPS where possible, 30 FPS otherwise. 24 FPS is just not enough.

Permalink - posted 2022-10-04