Why I shoot 24 FPS video
March 6, 2021
I record video with a LX100, so keep in mind that with different gear, your mileage may vary.
The LX100 offers the following recording options (I didn’t include the ones over 30 FPS as I’m not interested in those for this point).
If we bring it back down to the frame level, each frame is allowed respectively:
You can see that with the options that the LX100 offers, by shooting 24 FPS instead of 30, we can allow more bytes for each frame, resulting in an higher quality and more details overall (4.1 MB instead of 3.3 MB when comparing 4K MP4 for example).
I wouldn’t mind shooting in 1080p for the kind of work that I do, but the quality of 1080p MP4 or AVCHD on this camera is not remotely as good than 4K even if I later convert it down to 1080p.
Technically speaking, if I would downsize the 4K 24 FPS video by 4 to output 1080p, and if I kept the bitrate proportional, each frame would be allowed as much space than the AVCHD 1080p 24 FPS, but in reality, I’m able to export in 1080p from the first one to an even lower bitrate than the AVCHD version (15 Mbps) while having a nicer output (by orders of magnitude). This is more likely because I’m able to use much better compression algorithms in post that the LX100 can’t afford to compute in real time.
This means that even though 4K source video is pretty heavy, that’s the only way with this camera to get high quality video even when exporting 1080p at the end of the day.
The upside is that I can publish 1440p video on YouTube without upscaling, and this has the benefit to force YouTube VP9 codec, which gives a much better output than AVC1, which is otherwise used by default for low views videos that are 1080p or less.
By taking less pictures per second, we can expose each frame longer, which can be useful in low light situations.
That’s another reason why I consistently shoot 24 FPS, so that I can push the exposure longer than I could with 30 FPS, if I’m in a situation that requires it.
When I shoot, let’s say, 60 FPS, I can slowdown the video up to 2.5 times when I put it in a 24 FPS timeline, while I can “only” slow it down by a factor of 2 in a 30 FPS timeline.
Not a big deal, but might as well.
You probably heard many places online that by shooting 24FPS you get a “cinematic” look. I don’t really make the difference for the videos that I make, to be honest, but i don’t mind whatever looks it gives to my videos either.
So mostly for all the advantages I listed above, but especially the fact that I get higher image quality on the LX100, I prefer to shoot 24 FPS.