Tuesday Tip – How to Create a Slow Motion Video Using Optical Flow in Final Cut Pro X
Final Cut Pro X has a pretty cool feature called Optical Flow that allows you to create Slow Motion Video without having to install any additional plugins or purchase software. We shot the Diet Coke/Mentos video below on a Canon EOS Rebel T4i at 60 frames per second with a shutter speed of 125th.
Yeah, yeah, I know… anti-climatic is an understatement for the “explosion” we were going for. Keep in mind that this was our fifth attempt and I’m not about wasting poisonous consumables. In any case, you get a nice idea how much of the video is retained even when slowing the footage down with FCPX Optical Flow.
Here’s a little insight on how we did it: After dragging the clip into FCPX, I selected the portion that I wanted to be in slow motion then highlighted it. Next, I clicked on the retime drop down tab and selected one of the slow presets. I then clicked the retime icon again, chose video quality and selected Optical Flow. The video must then render out and that’s it. Super simple and the slow motion looks fairly good considering it comes natively with FCPX. Any thoughts?
FCPX, Final Cut Pro, Final Cut Pro X, How To, optical flow, post production, slow motion video, Tuesday Tip, tutorial, video production
Worked well. Did you shoot 720p 60?
@Andy Yes, you can only shoot 720p in 60fps on the T4i.
Hi Olivia, just checked on my FCPX 10.0.6 – the latest update – and you don’t have to actually cut the clip to slomo a section anymore. Just hit I and O in the project timeline to select a range and go to the retime menu. X will slomo just the section you’ve selected.
@Mike Awesome, thank you for the tip!
have you tried optical flow using whilst the camera is slowly panning/moving? i don’t always find the optical flow feature in FCPX useful in this particular scenario as the results are not always good
@Kuz No I have not. Do the frames seem to skip?
Thanks Olivia. Ive been applying optical flow to some handheld timelapse dolly shots (hyperlapse?) once the stills have been retimed, exported, reimported as .mov and stabilized, it seems to make smoother shots, not sure if it is interpolating and adding additional ‘created’ frames or what?
For 720p 60 slowmo, I saw a tutorial where you drop a 60p clip into a 24p timeline, then choose ‘conform speed’ in the retime menu, fcpx then plays all 60 frames captured in one second but at 24 frames per second so you get a true slowmo shot. Is this the same as what youre doing?
@Andy Oh, nice, thanks for the tip. No, we didn’t use that method but it sounds interesting! I’m sure there are some creative ways to slow footage down in FCPX as I’ve seen a handful on YouTube.
Thanks Olivia! I’m new and been using FinalCut just to do my basic editing and this is such a great info. Much appreciated!
I shoot 720p in 30fps , 50% reduction still works.