Ich habe mal bei Reikan / FoCal nachgefragt, wann die D850 unterstützt wird. Die Antwort kan heute (ich verzichte mal auf eine Übersetzung):
At the moment the Nikon D850 is not supported by FoCal, but it is coming!
Nikon has not provided an update to their comms library module which FoCal software uses to communicate to Nikon cameras. This normally happens around a month or so of the camera becoming available.
Once we have the updated software from Nikon it usually takes 3-4 weeks for an updated version of FoCal which will provide support for the camera.