I’m working with a single drone shot of 3 min, shot in 24 fps. The shot is smooth and looks great in real time, but I need to speed up a portion of it. 

I thought this was going to be simple … but it’s not. When I speed up the footage, it doesn’t look good any more. It’s kind of jerky, like if it was skipping frames. 

When I speed it up 200%, or 400% the footage, it’s OK, but anything in-between is far from perfect. Like 150% of the speed seems to be skipping frames. 

Even if I could work with 200%, the speed ramping to get there look choppy in-between. 

Is there some kind of math rules I should follow to make sure everything is as smooth as possible? 

I have tried with Media Composer, Resolve and Premiere and I’m having the same result. Any thought?

JPBU:

 When I speed up the footage, it doesn’t look good any more. It’s kind of jerky, like if it was skipping frames. 

That is exactly what it is doing - skipping frames.  The only way to speed up footage.  And in 23.976 fps each frame holds a large amount of real time action, so throwing some away can really be obvious.

The reason certain percentage look better (200%) is that the pattern of dropping is consistent and even.

Have you tried using Fluid Motion processing on the speed ups?  That is generally the best way to handle an issue such as this, BUT it is not perfect.  And depending on the motion involved may have really bizarre results.

Jef

Thank you for your reply Jef. 

So, I should stick to "even multipliers" to make sure it's the best it can look ? Like 200%, 400%, 600% ?

That is about the best advice.  But I would play with the Fluid Motion option in Timewarp.  Brutal renders, potential artifacts, but magic when it works out for you.

Good luck,

Jef