Rendering still images from video with varying results

[jürgenweissgerber]

Hello,

I created a timelapse at 25fps from 657 individual images using After Effects.
Now I have rendered this MP4 into JPEG still images using After Effects and only get 399 images with the 25fps setting. I don't understand it right away. Shouldn't this be 657 again?
Discovered by chance because I want to change my clips from 25fps to 30fps. These run better on the TV, or that's how they are set.
I set AE to 25 fps in project settings and under presets when importing, import the video clip and have individual images rendered.
Then I set everything to 30 fps, import the individual images and render them out in 30 fps. The sum of the individual images almost never corresponds to the original.
Does anyone have an explanation for this, since the newly rendered clips are not only shorter by the difference from 25 to 30 fps, but by a lot more.
Best regards
Juergen

After Effects 2023 latest Version

[Mylenium]

Sounds liek you're messing up framerates in your comps and possibly on render and potentailly also your comps are too short. Impossible to say what the exact problem is based on such vague info.

Mylenium

[jürgenweissgerber]

Hello,

well, I've been working with timelapse photography and editing it with After Effects for several years now. With a timelapse you can't really go wrong with the compositions because everything consists of individual images. If I have 650 frames and the comp is set to 25fps, the film will be 26 seconds long.
Logical.
But if I set 30fps in the comp and render at 30fps, it will only be 21.06 seconds long.
There are always 650 images.
Why are clips too short?
You can make clips as short or long as you took photos.
Everything has worked wonderfully over the years.
I only noticed the error now because I wanted to split a clip with 26 seconds and 650 photos back into its individual images for interpolation. But here, thanks to After Effects, a different number comes out, namely only 399 photos.