Thank you for your reply and the valuable tips.
Yes you are totally right. But sadly I can’t get the charuco code working in python.
Do you have a working python script by any chance for open cv 4.10.0?
(But any other version would be fine too, as I am able to switch.)
I already asked for help here and here.
You are referring to more “steep” pictures? That was the “tradeoff” I described with steep angles vs not filling the whole image plane.
Okay, then I will prefer this approach and try to have as much of the pattern in my FOV as possible.
P.S.: One may ask why I am not using 450 mm as focus distance. The answer is that I have markings on my dial at 400 and 500, so I can repeat measurments here. Where 450 lies would just be a guess, since the scale is also non linear.