Is there a way to change the fps on an existing animation without changing the time? For example I have an 8 fps 1 min animation and i want change it to 24 fps but keep it 1 min.
If I’m not mistaken, you can set such in the rendering settings, but I do not animate, so it may be wrong. Just look in the rendering settings and you should find it out.
Michelist
If you change the fps in the Render Animation settings to 24 fps then the result will be a 20 second animation (60 seconds * 8/24).
[Edited to correct a simple arithmetic error.]
What you need to do is insert Hold frames so that every frame of the original animation is held for an additional 2 frames before the next keyframe.
That will give an animation that has three times as many frames and so will last three minutes at 8 fps.
The image you see will change at 8/3 fps because that’s all you have to start with.
You Insert Hold frames by selecting the original range of frames, which will then be highlighted on the timeline, then right-click on them and select
Hold Frames -> Insert Multiple Hold Frames then set the number of frames to 2 and press OK.
Then when you change the fps to 24 fps, you’ll have an animation that lasts for 1 minute but the image you see will still change at a rate of 8 ‘images per second’ because that’s all you had to start with.
If you want a smoother animation, you have to paint your own inbetween ('tween) keyframes to replace the Hold frames.
If your animated image is a moving object that simply moves but does not change in appearance, then you’d be better off using an animated transform mask and the animation curves docker.
That is an entirely different subject area and is very confusing if you’re just starting to learn about it.