23.97 - 24 - 25 wich one?

[Patrick Tresch]

Hello,

I would like to know your expience shooting 24p for cinema release.

When you aim at 24p do you shoot 23.97 or 24p? Does the DCP play a 24p frame rate? Do you accelerate the framerates for the cinema mastering from 23.97 to 24p? Is the DCI standard 23.97 compatible?

Why would anyone choose to shoot 23.97 (and not 24p) for cinema release?
Do you change from 23.97 to 24p when you enter the edit room?

I'm in the 25p continent and happy to have one master for all needs. So I also wonder if we should transcode everything to 25p and have that universal master.

Any input is wellcome.

Patrick

 

[William Long]

No, it's just that the Americans messed it all up from the beginning. :emote_couch: Ha ha!

 

[Phil Holland]

For me it depends on the project and client mainly. Various pla

Most of my at speed work is 24 or 29.97 time base outside of the HFR stuff. Made a pretty hard stop on 23.976 unless I'm tasked to do so.

At this point in my career I've mastered everything from 23.976 through 120fps with PAL in there too.

As streaming evolves as well as digital delivery, much of this isn't too much of a headache anymore. Screens are evolving too and that is needed as well. Eventually it won't matter at all and we'll be in the happy days of choosing whatever fps you want to tell your story in. We have a long way to go, but it is happening.

If you're bored and want to learn about the late 1800s, google up Westinghouse and there's a few explanations of why we don't use 40Hz and why 60Hz was chosen after 50Hz due to arc and incandescent lighting flickering of the era. This eventually carried over into broadcast crap.

Theaters had it right from the get go honestly. Things were happening at as low as 16 fps then 22-26 in the 1920s. 24 became the go to because it was smack dab in the middle and did the job as well as looked pleasing to the eye. Sort of a sweet spot for what is often referred to as the "illusion of motion" from long ago. The visual difference between actual projected 24 and 25 fps material is pretty much nonexistent.

PAL was introduced in the 60s and that was actually the problem. Though not really because 25p fell in that 22-26fps range.

The real culprit is broadcast in general. As more and more things go digital, this will all be a forgotten blimp in the world of headaches of making content. Much like interlacing being a headache for some along the way, it's pretty much a non issue now.

Most major streaming services now can handle content delivered in 23.976 to 60p with both 25 and 50p in there with no headaches.

 

[M Harvey]

I don't know the answer, but I do know this: be sure to tell your sound recordist which you settled on!

I personally love the idea of just shooting straight 24, but almost always shoot 23.976, just because that's "what people do" and you have to have a conversation with the producers or whatever otherwise (there are a lot of other creative or equipment things I'd push for before an invisible frame rate difference). There's no technical reason for preferring 24, except that I'd just like to do my part to leave the 23.976 behind as an artifact of obsolete technology.

 

[Patrick Tresch]

It looks like that 23.97 is not a DCI standard (no fractional frame reates) and in this case we have has to use 24p for mastering.
It also looks like that when shooting 23.97 you'll have to change it before editing (ideally) or during the mastering by speeding up the sound by 1/1000 to put all media to the same timebase 24p.
As some cameras don't do 24p, it's probably best to shoot all cameras at 23.97 if you have two cameras rolling at that speed to avoid desynch.
It also looks like 24p is more prone to create an 29.97 fps master than starting with 25p. So if the film is mainly intendend for NTSC folks it's kind of logic to shoot 24p.
For sound it doesn't matter if your TC is 23,97, 24, 25, as 1 sec is one sec and the synch is made at 1/48000.

I hope I didn't got it wrong ;-)

PS: It's so easy to shoot 25p.

 

[Blair S. Paulsen]

Good to revisit this topic as the tech iterates. Agree the fractional frame rates should be deprecated. I will note that for many years, I stuck with 23.976 and 29.97 and never had post issues. OTOH, I knew several projects that had major headaches with 24 during post. Since the SR tape shortage caused by the earthquake in Japan, and more solid state recording devices on sets, it really shouldn't matter anymore. That said, CYA...

Cheers - #19

 

[M Harvey]

For sound it doesn't matter if your TC is 23,97, 24, 25, as 1 sec is one sec and the synch is made at 1/48000.

I may misunderstand—are you basically saying that your TC box takes care of sync, no matter what the settings? Or that it doesn’t matter if your camera and recorder are set to the same frame rate?

1 sec=1 sec, but if that 1 sec is divided into 24 fps on the camera but 23.98 fps on the sound recorder, they will drift out of sync in post!

 

[Patrick Tresch]

I may misunderstand—are you basically saying that your TC box takes care of sync, no matter what the settings? Or that it doesn’t matter if your camera and recorder are set to the same frame rate?

1 sec=1 sec, but if that 1 sec is divided into 24 fps on the camera but 23.98 fps on the sound recorder, they will drift out of sync in post!

What I understood is that it will remap the time to be adjusted to the second and not to the frame count... I could be wrong but I assume be it 24p ou 60p 1 second is still 1 second for sound. The software would take care to remap it in synch with what ever time base you use...

 

[Phil Holland]

Good to revisit this topic as the tech iterates. Agree the fractional frame rates should be deprecated. I will note that for many years, I stuck with 23.976 and 29.97 and never had post issues. OTOH, I knew several projects that had major headaches with 24 during post. Since the SR tape shortage caused by the earthquake in Japan, and more solid state recording devices on sets, it really shouldn't matter anymore. That said, CYA...

Cheers - #19

In the 2000s I presented a case for a metadata driven system to toggle between content displayed at 23.976 up to 60fps with the idea that all modern screens would support up to variable refresh rates up to 60hz. Revised that a bit in I think 2012 to support up to 120fps, which several sets can do now in 8K. It will take a while for the world to get there, but in my vision you can air a commercial at 30fps and cut to a basketball game at 60fps and the sigma will trigger wha the television does. Somewhat similar to adaptive resolution and stream rates currently. And this would only need to be done for content shot in HFR. I agree that fractional frame rates are pretty much unnecessary. Still parts of the world that need them.

Once we are through the technological adolescent developed box that we've been confined to, eventually it will be just be a choice of how you want to capture and display your content one day. Going to probably take a decade or two to get closer to it.

For the imaging professionals here. Consult with your distributor, client, etc. before you roll on your shoots. Streaming services allow for a broad range of finishing frame rates now, which has expanded beyond what typical broadcast limits forced you in a bit ago. Most now do support up to 60fps. Theatrical as well, but lots more to consider on that front.

 

[Zack Birlew]

From what I understand, these days, it doesn't matter unless you're filming for PAL, the classic situation really. I've been used to 23.976 (23.98) since the DVX100 24p days and from what I remember of it, it's mostly been personal choice whether to do straight 24fps for a while until Bluray and streaming got big to the point that there's no difference, anything works now. For audio, it does matter to a point and would save some headache in post to be sure what you're doing ahead of time and even that can be stretched and shrunk into place to fit to a degree. On my first feature I wondered if we should just do straight 24fps but I instinctively thought 23.98 would be the "correct" choice and went with that. But for PAL, even with all the tools we have today, that stuff will still mess you up if you get the camera and audio choices wrong.