Thanks for the tests, especially looking forward to working with the 17mm Canon and Cambo adapter. Hopefully the 17mm will have the same corner sharpness.
One note, on the Fotodiox adapter, my Nikon to GFX arrived yesterday. Adapter seems well made, solid, however I was not pleased with how it was shipped. Basically placed in a thin lightly padded envelope, nothing around the adapter and given to the mercy of UPS. No box, period around the adapter. So both flanges (GFX and Nikon) were exposed to damage. Seemed to come through OK, however. I have tried the adapter with several Nikon lenses but not used them on the the GFX, but with Fotodiox/Nikon aperture control is possible on Nikon lenses with F mount like 14-24 and 70-200. Will miss the VR however.
Paul Caldwell