In reality an A button would be the one which I would never use. I discover virtually every button on the back of my cameras to be very efficient time savers. It could be better to release, finally, an actual FDTZ adapter, with full legacy assist with AI, AI-S, AF & AF-D lenses from the F-mount system! That could be the retro accent really worthy for legacy users to be bridged to Z system. At the Party Tour for the launch of Z8 in Italy, I tried a 55mm f/3.5 micro-nikkor by way of FTZ II… no EXIF, no aperture …
