EOS R5 Mark II - How does audio play back when shooting slow motion?

[LaneW]

I haven’t been able to find an answer for this. My new R5 Mii will record audio at 120 fps now which is great. But I don’t understand how audio works. Obviously it records at the higher frame rate, but the audio slows when played back, say, on a slower frame rate.  So, looking at a slowed clip of a flock of vocal birds is not going to work - or am I missing something?  Is there some Canon magic that keeps the audio normal, or do I just get a short audio file for a longer video clip?

[p4pictures]

According to the manual, audio is not recorded when shooting in high frame rates.

https://cam.start.canon/en/C017/manual/html/UG-03_Shooting-2_0050.html 

See the 2nd bullet point under the menu screen.

[shadowsports]

Hi LaneW,

It's been awhile. I hope you are doing well.  Brian is correct about the R5 Mark II. Only Canons Cinema series cameras can record a separate audio track to the SD card during high frame rate (S&F) recording.

[LaneW]

Brian and Rick,

Thanks for the responses.  So, digging in more deeply, I have learned that I can, in fact, record audio at 120 fps - but only with High Frame Rate disabled, as I think Brian was referring to.

So, now I find that I have a video (on my SD, not CF card - so I have to find that setting) and the video has audio on it. But it is not a separate audio file, just part of the mp4.   You guys are saying that I won't get a separate audio file, but I could swear that I read in the manual that I can - and now I can't find it.

I still have a lot to learn about this Mark ii upgrade!

Thanks

Lane

[p4pictures]

So if you record at 120fps and the camera captures movement and sound for 10 seconds.

Then in the edit you slow down the movie to 1/4 speed or 30fps. The movie now lasts for 40 seconds. However you only captured 10 seconds of audio, and If the sound is slowed down as well it will sound like a 1/4 speed vinyl turntable. With slow motion footage you may need to work with some additional audio or do something with the captured audio independent of the footage. 

[LaneW · Accepted solution]

Brian,

Thanks.  This makes sense. Apparently I would need to take the partial audio file in my editing software and copy/repeat it in the timeline if the sound fit with the video.

[jackleenandrey]

Great question! When recording at 120fps, the video is designed for slow-motion playback, but the audio isn’t stretched—it typically gets dropped or shortened to match the slowed footage. That’s why you’ll often see slow-mo clips with music or added sound effects instead. For real-time audio, you'd need to record it separately at normal speed and sync it in post.

4o

[LaneW · Accepted solution]

That answers my question. Thanks!