To illustrate the 100/1.6 Rodenstock also works on FX cameras, here is a night snapshot with the lens on the Z6. The timber pile was entirely lit by moonlight so having a fast lens and ISO 3200 allowed me to capture the scene. The corners weren't that bad as this is not infinity focus, however I might have trimmed the frame ever so slightly. As said above, using the Z fc alleviates any worries about frame coverage or poor corner quality.