How to Fix Baffling Fast Playback of 24FPS from BMPCC 6K?

I've just finished a shoot for a world-famous brand using 2 x BMPCC 6Ks and a BMPCC 4K. I'm fairly horrified to discover that all the footage shot at 24fps in 6K and 2.8K on the Pocket 6Ks is playing back slightly too fast, almost like a timelapse. It does this everywhere - in camera, using the Blackmagic RAW Player and in Da Vinci Resolve. The footage from the Pocket 4K plays back perfectly. The 120fps seems fine, but as the difference with the other footage is slight, who knows if it is exactly right. Bizarrely I've just done a test (the day after the shoot) and it seems to be recording and playing back 24fps just fine.

Does anyone have any idea what this could be? Am I missing something really simple here? I've done a great many shoots using these cameras, but this was the first shoot since updating to 7.3 and my first experience of this. And it's very odd that it has happened with 2 x Pocket 6Ks - would both camera ops make the same mistake causing this?

Of course it would happen on the biggest shoot of my life so far... please help - the pressure is on! And if I've done something stupid, or if there is some kind of glitch somewhere, any ideas as to how it could be fixed in post please? I can slow the footage of course... but have nothing to guide me on how much.

Thank you all in advance!

Only idea I have is that you were unintentionally shooting in Off Speed on the 6K's.

A co-worker recently hit that button without realizing and got unintended slow motion for a lot of his B-Roll.

Try this: create a new project and before adding any footage, go to preferences and under Conform options, change the mixed frame rate playback option to "none". Frame rate of project would be 24fps, of course.

Then put your "fast playback" footage on the timeline and see whether what you have is acceptable, compared to the actual 24fps footage. If so, these are the settings you want to complete and export the project.

Thanks Jim - I don't think that's it unfortunately as we were also intentionally shooting in Off Speed sometimes in the shoot as well, so have slo-mo footage which is quite distinct from this stuff, which is oddly sped up. Appreciate the thought! The difference seems to be about 20%, so slowing to 80% 'fixes' it as it were - albeit far from perfectly.

Only idea I have is that you were unintentionally shooting in Off Speed on the 6K's.

A co-worker recently hit that button without realizing and got unintended slow motion for a lot of his B-Roll.

Thanks very much for this John - unfortunately it didn't yield a different result. Everyone I know in the field is very perplexed. I'm going to do some more tests to see if I can replicate it. Someone has even suggested sabotage...! As you can see, clutching at straws now!

Try this: create a new project and before adding any footage, go to preferences and under Conform options, change the mixed frame rate playback option to "none". Frame rate of project would be 24fps, of course.

Then put your "fast playback" footage on the timeline and see whether what you have is acceptable, compared to the actual 24fps footage. If so, these are the settings you want to complete and export the project.

Can you share one of the shorter problem clips for testing?

Thank you - I'd love to but cannot as its all unreleased and confidential. BM have some raw clips though which they are testing, they acknowledge the issue and can see from the metadata that we dont appear to have made any errors, so all still remain perplexed at this point!

Can you share one of the shorter problem clips for testing?

let me know if you find a solution to this i'm having exactly the same problem.

Thank you - I'd love to but cannot as its all unreleased and confidential. BM have some raw clips though which they are testing, they acknowledge the issue and can see from the metadata that we dont appear to have made any errors, so all still remain perplexed at this point!

Can you share one of the shorter problem clips for testing?

The just released 17.2.2 includes Support for Blackmagic RAW SDK 2.1.

Maybe that helps here?

[quote="darreleve"]let me know if you find a solution to this i'm having exactly the same problem.

Did you ever find a solution to this? It's just happened to us again on a shoot - the final day of footage is ok but it is all sped up for two days and on one other day the speed is fine for some takes and then sped up for others.

And there is no indicator whatsoever as to why it is happening. I have just rigged up both cameras filming a clock for 5 minutes and superimposed the image. Absolutely no speed issues whatsoever. The only other variable is that we were using DJI RS2 Pro stabilisers, but surely they're not interfering. Aside from that we are shooting normal speed one minute, then switching to off speed stuff before switching back.

We have the latest camera updates on both cameras, all frame rates match from camera project setting to what we shot with, to the project setting in Resolve (25fps this time).

I had a similar problem. After trying different things, I just right clicked over the clip on the timeline, went to Video Attributes, then Video, then changed the Video Frame Rate to 24. It started to play smoothly.

I just had this problem and figured out a solution that worked great for me.

I recorded in 24/50 with off speed recording on, which has always just allowed me to hit the HFR button to switch to slow motion. This time however I shot 2 interviews, and the audio was normal but the clip was reading as 50 fps and the video was playing in hyperspeed out of sync with the audio.

So after freaking out, since the audio was the right speed, I duplicated the clip in the project window, then right-clicked on the duplicate clip and hit modify > interpret footage > interpret footage as 24 fps.

Then just dragged the video from the 24fps version onto the original version with the good audio and it synced up great and looks like I shot it in 24 fps.