@duerer I see what you mean now.
But the dimensions of your Viewport are not fixed and neither is the aspect ratio of the Viewport…so you’d need to somehow ‘drive’ the Camera dimensions with the Viewport dimensions…
Smells like a job for Python 🙂
I do not know how this is being calculated internally, but doubling the Sensor Size, like you did does seem to get close to what you want (at least if the aspect ratios are (almost) the same…).
