Brussels, today 22/11. Judy Blue Eyes.
This is my first shot with the Nokton 50/1.0 on the Zf. Wide open, which you may have guessed. That lens is pretty sharp wide open but above all very contrasty, reminding the Noct. The blacks are quite black already, when in focus of course. At 1.4, sharpness increases significantly and color saturation rises a bit. Rendering reminds Summilux R 50/1.4. Vignetting is strong: "clipped corners" (see also 50/1.2 AIS), so cropping to 4:3 would be a reasonable way to handle it uniformly. Low barrel distortion. Low focus breathing. Focus plane is not flat, the corners are bent towards the rear (much less at short focusing distances, apparently). CA not worth mentioning, LoCA is there but not outrageous, same with coma as far as I could check (at daytime).
Physically it is a massive lens with reasonable dimensions (62mm filters), and shorter than most Z lenses. No plastic parts. The focus ring action is perfect. The aperture ring is in the front, à la Zuiko, and provides 1/3 stop clicks. Metal shade was fortunately provided in the box (beware of not losing it: expensive replacement).