I'm often using the Viltrox 13/1.4 or 23/1.4 on the FX cameras, in particular with the Z9. Makes for a nice and small -- OK, the limit for perceived smallness is the Z9 of course -- combination. The Viltrox line delivers very respectable performance and on the FX Nikons the camera automatically records in DX mode. 19-20MPix suffice for many applications of mine. Then there is the endearing and tiny Voigtländer 35mm f/1.2 which I purchased for the Z fc, but it often manages to meander over to the big Z9 brother.