C4D camera calibration

[jojorender]

Hi all,
not a corona issue, but I need some help with C4D camera calibration tool.
I get mostly wrong focal length, cam position or crazy film offset values, even when I get all green “solved” marks.
Does anyone know a good tutorial?
I usually “eyeball” the cam but now I have a larger project putting furniture into existing images and I need a better way of calibrating the camera. Being a "little off" might still work in a large exterior scene but not in a small room.
Most images I get have no metadata and real cam/ lens info is not available.
I can get approx. room measurements from floor plans.
Any tips?

[Beanzvision]

Hi, maybe grab a coffee (or a beer) and check this out. It's a long one ;)

Hope this helps.

[jojorender]

Thanks Beanz!
The first tut was new to me. Need another beer to finish it but has some good info already.
I wonder if lens corrections tools (in camera & apps) mess with the image geometry so much that cam matching gets more difficult than it should be.
I’ll gladly let AI do this kind of task for me. Any AI tools out there for this?