Problems changing the interpolation type and speed

@phmydcnd  Maybe I can help? What are you aiming to do? I think the settings OP wanted to change are in the VideoCamera.ini file, for the cinematic camera accessed by clicking TAB, then choosing a camera point by numbers 5, 6, 7, 8, 9, 0:

[Default interpolator parameters]
DefaultInterpolatorType = Linear
DefaultInterpolatorTime = 2.0

[Camera 5 interpolator parameters]
InterpolatorType = Linear
InterpolatorTime = 2.0

[Camera 6 interpolator parameters]
InterpolatorType = Linear
InterpolatorTime = 2.0

Changing Linear to EasyIn  / EasyInOut for difference in start speed and end speed; and 2.0 to whatever number you want, the higher the slower the camera pans (seconds).

Open the file in Notepad, or some other editing program, and make sure it is not set to Read Only, so that it can be edited. (right-click on it and choose Properties). Change the number, and close the file, pressing Save when asked. Patching and Repairing in Origin will reset it to default, so make a copy, or remaking the edits then is necessary.

Here is a good video on it. It's from 2014 though, and it seems the file has been changed since then. When testing this I needed to change both the Default interpolator parameters and the Camera 5 interpolator parameters (to the same values) for it to take effect in game. I didn't see any difference also changing Camera 6 interpolator parameters, I tested The Sims 3 Camera as well. But I never record, so maybe it does something I didn't detect; you'll have to experiment.
https://www.youtube.com/watch?v=KNVB0_OWKCw