I am running some QT files through Motion 3's "optical flow" for slow motion. It took me a bit to get some things figured out, but it finally seems to be working correctly. The problem is when I have people walking through the frame in front of other objects, it creates this odd artifacting that looks like watery waves or a shimmering force-field around them.

It's really bad and makes the footage unusable. Is there any way around this? I'm slowing things down to 75%, would slowing them down LESS be a better option? I mean, I could slow the clip down to 95%, and then take that exported clip and run it through again at 95% and then again and again, but it already takes so long just to do one clip, I'd really like to find a reasonable solution.

Thanks

I use After Effects and Final Cut, so I'm not familiar with that particular effect. I think final cut does a fine job adjusting the speed (but AE is supposed to be much better when you know what you are doing). The point is if you just want to slow it down give Final Cut a try, just see if you prefer it with frame blending on or off.

That's how optical flow should look like, it may not work for all kinds of scene. Try using Frame Blinding instead.

I had a similar problem when using "pixel motion" to get a slo-mo effect in After Effects (probably similar to optical flow in FCP). I switched to frame blending and it was much better.

As Moayad mentioned, pixel motion or optical flow might work well for certain types of scenes and not so good for others. Just have to test it and see.

Thanks for the replies. I tried all kinds of speeds just in case I could sneak by the problem, but I cant. I'll try a frame blending technique for these instead.
Thanks