That's so funny Akira 

Yes, they appeared out of the blue and the atmosphere was quite bizarre. 

A nice curved transformation of the graphic elements by the 16mm lens.  And nicely framed and presented.

 Thank you, much appreciated.

I was just leaving...

That's so funny Akira 

The only SB-800 mode that functions as expected with the FV(lock) and Nikon Z8 is [AA] or Auto Aperture which uses the sensor on the front of the SB-800 rather than the image sensor in the camera. Perhaps FV (lock) is just not compatible without a separate sensor such as the ones in the D850's finder. I have some ideas why FV (lock) may be fundamentally incompatible with the image sensor in a digital camera, DSLR or mirrorless. Now I'm wondering if there is a way to lock in the exposure after taking a shot: shutter, aperture and flash duration. Also the same problem I'm having with the SB-800 is the same with the SB-400 and SB-700.

I'll talk to Nikon but last time I did whoever I talked to thought the *.nxd and *.nka files were presets rather than potentially unique to a single image.

Dave