Danke...so it's SONY EX1R and careful planning, shooting slow mo to begin with, play with shutter speed, and playing with Optical Flow, tried 10%, went down to 3 or 4% and saw how it worked - thing is to have good lighting (better than I had), clean, non-busy BG, not a lot of movement from the subject.

......., not a lot of movement from the subject.

That is true....
I did some testing with splashing water and Timewarp in AE (which is said to be an almost similair effect as Optical Flow) and the effect at 20% was already hilarious. AE had no idea what was happening.... I shot 60frames over 25 at 1/250... the software can't figure out which drop is going where: too much movement in all directions. Maybe I'll post it after christmas (to busy now ;-) )

Anyway: great work.
You seem to have managed to avoid most of the 'cross-fade-feet' that shows in your test. That was really the only real giveaway of the postprocessing.

Basically there needs to be no other movement beyond the subject and no moving planes crossing each other. I tried this with a tennis swing and it was a complete disaster. The racket crossing the body resulted in the "ripple/water" effect.

You're both right about movement - and thanks only to editing you don't see the awful artifacts of feet, unless you look real carefully at the very end of almost every ultra slow mo shot.

Thanks for posting. Great work. I really like how there is no strobing with the super slo-mo shots. I guess that is a function of the software doing a great job.

Did you have detail turned down or off on the EX-1? Your footage has nice soft edges. Not very "video-ish" at all.

Also, did you test the super slow-mo with normal shutter like 1/60th or even 1/48th? It would be interesting to know if you could still get away with 4% with a slower shutter and more motion blur.

Good questions - no I never (my mistake) tried shutter below 250, probably even better results (I think) if I went to 120 or so, as far as better exposure/light. I shot everything at 24p so that helped get rid of "video" look, more filmic, but also used Magic Bullet Quick looks and three way color corrector in FCP to make it a little better than no color grading.

And Optical flow did OK, again not Phantom quality but hey at least I know in certain circumstances, under the right conditions,etc I can shoot ultra slo mo with my EX1R and Optical Flow.