I had noticed it for quite some time: if you use a certain slow motion effect, something doesn’t run smoothly anymore…
It happened again recently: Topaz produces JUDDER.
More specifically: if you use a 3x slow motion/frame interpolation with Apollo, it is not homogeneous.
(For example, if you want to turn 30 fps into 90 fps so that it doesn’t jerk on VR glasses).
Instead, you get a sequence, a series of 3 images that always show two (relatively) large movements followed by a (relatively) smaller one.
It’s not exactly pretty.
This is probably due to the way the models work.
They always generate a certain (unfortunately not freely configurable – why not, actually?) number of intermediate images.
The higher this number, the more accurate the slow motion/the fewer the motion artifacts, especially with fast movements – in my observation – while at the same time achieving higher efficiency, at least if you need stronger slow motion.
And this is precisely where the problem lies.
Apollo always generates 8 steps (from one in the original file) and Aion 16 steps.
If you now select Apollo for a 3x stretch (regardless of whether it’s SloMo or frame interpolation), it takes two 3-step steps and one 2-step step in the image sequence it generates, which consists of 8 images.
In my opinion, the resulting error (judder) is no longer professional.
Now I’ve taken Aion. It takes 16 steps from one in the original.
Of course, this doesn’t work out exactly with 3 or 5 times stretching, but the difference is significantly smaller; it actually takes one 6-step and two 5-step stretches for a 3-fold stretch.
At least I didn’t notice this on my screen anymore, but the bitter pill is that I now have to wait twice as long, e.g., 10 hours with Aion instead of 5 hours with Apollo… (for an fps conversion).
Speed 3x slow motion/frame interpolation with 4K and RTX 5080
( with good utilization of the same) :
Chronos: 6.2 fps (too many artifacts during fast movements, only useful for simple fps conversion – where ‘motion studies’ are not important)
Apollo: 7.6 fps
Aion: 3.8 fps
Attempt at a conclusion:
I currently really like using 3x slow motion, as it is often the choice that creates a significant time stretch without resulting in too little movement (which makes it boring) in the image.
On the other hand, fps conversion is becoming increasingly important for VR headsets, and a tripling is often desired. (30 fps to 90 fps…)
It should be possible, with minimal effort, to ‘command’ an Apollo variant that generates 9 frames per step, which could then make three homogeneous steps of 3 with a 3x stretch…
kind regards
seifenchef
