Fps problem during a camera motion...

[sandrog86581053]

Hi everyone!

I have some problem... I'm working on an animation, which basically consists of paintings. Animation is done at 12 fps, so all of the sequences play 12 paintings in 1 sec. Everything was fine, until I decided to use an after effects camera to create a parallax effects... Because the composition is at 12fps, the way the camera moves is pretty jittery there... When u look at the any part of an animation, your eyes start aching... I understand that animation at 12 fps can't be as smooth as the one with 24fps, but still - something feels wrong. Any ideas?

[Martin_Ritter]

This is not wrong, but the effect of 12fps.

To get a smooth camera movement, you should create some pre-comps with your 12fps animation in it and put those into an 24fps comp with the camera in it.

Before you get into this, you should try another way first:

On position property (or whatever you have animated on the camera), add this expression:

posterizeTime(24);

I know this works for the opposite direction (get low fps in a higher fps comp), maybe you are lucky and it also works in this way.

Cheers,

*Martin

[Rick Gerard]

There is a relationship between the speed of movement and the frame rate that causes stroboscopic effects. It is often called Judder. There are critical speeds that just cause movement to look bad. In the Cinematographers Handbook, these speeds are called critical panning speeds and there are charts that help camera operators avoid the problem.

Fortunately, the solution for you is very easy. Leave the timing the same for everything but change the composition frame rate. You will still get the classic 12 fps look - every Buggs Bunny cartoon ever made, but camera moves in and out of the scene will be smoothed out. I'd start with 24 fps comp settings. If fine-tuning the speed of the camera move does not fix the problem, then changing to 29.97 should help.

Here is a link that on Judder. I hope it still works. Check out the article I wrote: FAQ: Why does horizontal motion stutter (judder) 

[sandrog86581053]

Thank you very much for your explanation Rick. To be honest I tried the solution you suggested before posting the question here and it worked. The thing is, what should be the final output fps then... I have lots of scenes saved as different AE projects and all of them are at 12 fps... At some point I will need to render them all and merge into 1 file... So what should be the final render fps be? 12 or 24? Let me describe the process of how I'm doing stuff in the project:
1. I import the animated paintings as png sequence in after effects.
2. Before moving them into composition, I change their frame rate to 12fps from 'interpret footage > main > frame rate'.
3. Then I place the sequence into composition. (It automatically sets the composition to 12fps.

So now the question is: What is the final ouptut fps and won't things get messed up, when camera moves at 24 fps and png sequences at 12... ?

Thanks in advance,
Sandro G.

[Martin_Ritter]

My reply is gone thanks to the "better user experience" of the new forum - let's try again:

I wrote something like:

Juttering camera is normal at 12fps. To get around this, you should place your 12fps animation in a 24fps comp. Also, you have to put the camera in this 24fps comp and make the camera movment there.

Maybe another way would work:

Add this expression on every property you animated on the camera:

posterizeTime(24);

This works when you want a lower fps animation in a higher fps comp - maybe you are lucky and it also works in the opposite direction.

I hope this answer is now remains.

*Martin

[Rick Gerard]

 All you should really have to do to smooth out camera moves is change the composition frame rates to 24. No need at all to mess around with posterize time. You may even get smoother animations if you set your image sequences to frame blending. Render times will go up with either method but it might be worth it.

That is actually helped additional multiplane sell animation is done. Only 12 images per second are drawn for the animated characters, each of those cells is photographed twice, but the background images are mu in the multiplane rig for every frame. The process was invented by Disney and somewhere on this one I posted a link to a video where Walt himself was explaining the process.

(edit) Found it:

https://m.youtube.com/watch?v=YdHTlUGN1zw