I tried out the 4k@120fps slow motion and the video file was saved to the sd card as 4k@29.97 fps see attached file

Yes, everything was saved as a slow motion file...

Yeah, unfortunate and saw that right after I purchased a few weeks ago. Really would have liked to have it saved as 120 and slow down as needed in post.

Vtcats Posted at 5-15 11:25
Yeah, unfortunate and saw that right after I purchased a few weeks ago. Really would have liked to have it saved as 120 and slow down as needed in post.

Dear John,

Thank you for your feedback.

Upon confirming with our technical team, this situation is normal. Firstly, it can be judged by the shooting mode you used is slow motion, under which the 4k @120fps can only be supported.

Moreover, the frame rate is the frequency at which consecutive images are taken per second. With that being said, for 120fps, the number of images captured per second is 120. The playing speed is 1/4 of the recording speed to get the slow motion affection, that's why the frame rate is about 30fps when playing the video or checking in property.

We hope this clarifies your confusion. If you have any questions, please don't hesitate to contact us for further assistance.

Thanks for choosing DJI!

Best regards,
Vera
DJI Customer Support

Vtcats Posted at 5-15 11:25
Yeah, unfortunate and saw that right after I purchased a few weeks ago. Really would have liked to have it saved as 120 and slow down as needed in post.

totally agree with you

jaybee2786 Posted at 5-16 02:58
totally agree with you

I guess the question is, why didn’t they? While I understand this is not mirrorless, it seems most cameras that have 120p, will play back at 120p.  Is there something technology wise that prevents them from doing this?, or was there a cost savings? Etc

jaybee2786 Posted at 5-16 02:58
totally agree with you

Hey Jaybee,

   Are you sure you were recording with the main lens on this? I think, but not 100% sure, the secondary small explorer lens has max of 4k 30fps, it might have been that you actually switched to secondary small lens during recording i.e. while zooming etc, and that would switch your video to 30fps . Not sure if this is the case, but I had a similar issue if I used zoom function during recording and my video would switch to 30 fps. Also not 100% sure, it might be that if you use any zooming during recording, it switches to 30 fps as I had that. Hope this might be helpful.

Thanks, Mike.

That's a really low bitrate too!!!

BrianKushner Posted at 5-16 09:16
That's a really low bitrate too!!!

Hi BrainKushner,

I think this is the zoom lens being used. I had a similar result with it. It is a great way to zoom, it is just it might be limited to 30 fps by default I think, unless I did not properly switch it to higher frame rate.

Thanks, Mike.

jaybee2786 Posted at 5-16 02:57
Dear John,

Thank you for your feedback.

Does this mean that if I shoot in slo mo and then speed it up 4 times, it will be the same as regular speed 4K 120fps?

djiuser_f7anjJoIiyeq Posted at 9-6 17:02
Does this mean that if I shoot in slo mo and then speed it up 4 times, it will be the same as regular speed 4K 120fps?

Yes, that is right. I suspect that DJI saves the video as SlowMo with 30 frames/s, because most users would make a SlowMo out of 120 frames anyway.  The bit rate is not really low either, but within the specification of the Mavic 3 (34734 kbps * 4 = 139 Mbps).

OlliM1971 Posted at 9-7 00:14
Yes, that is right. I suspect that DJI saves the video as SlowMo with 30 frames/s, because most users would make a SlowMo out of 120 frames anyway.  The bit rate is not really low either, but within the specification of the Mavic 3 (34734 kbps * 4 = 139 Mbps).

If its really 120fps slowed down to 30fps..... can you speed it up to the pace that you desire?

Indeed! Faster is usually less critical than slower. It should look very smooth in real time :-). However, 120 frames/s is usually not your target frame rate and your devices have to support it as well…

I can't believe the camera can do 120fps!! Its like a dream!

You could just use the newly released Topaz Video AI version 4 ( https://www.topazlabs.com/topaz-video-ai ) then you can shoot at 30 fps continuously and then selectively change the parts of the clip you want in slow motion, This keeps continuity during the film.