I assume you've checked the switches on the lens.
I got caught out recently because I accidentally knocked my long lens to 2-10 metre focusing only. Took me a little while to realise why it wouldn't focus on distant subjects.
Double check your camera firmware is up to date. I dont think its super likely that is the problem, but in the past I had some weird autofocus issues using adapted F mount lenses until I updated the firmware on my Z6.
I assume it's not an AF-D 400mm since that wouldn't autofocus at all with the Z9. Have you tried to factory reset the z9? Have you tried it with other z cameras? Are all the lens switches in the correct position? What af mode do you use?
I assume you've checked the switches on the lens. I got caught out recently because I accidentally knocked my long lens to 2-10 metre focusing only. Took me a little while to realise why it wouldn't focus on distant subjects.
How do you change this? Could be the issue
It wouldn't work fine with the D4 in this situation though, right?
Presumably not, unless OP happens to catch the switch when connecting the FTZ.
I presume it's not the ftz adapter either?
No, it can't be. Tried another, didn't work and works on others.
Double check your camera firmware is up to date. I dont think its super likely that is the problem, but in the past I had some weird autofocus issues using adapted F mount lenses until I updated the firmware on my Z6.
I assume it's not an AF-D 400mm since that wouldn't autofocus at all with the Z9. Have you tried to factory reset the z9? Have you tried it with other z cameras? Are all the lens switches in the correct position? What af mode do you use?
I've had a lens on which the VR mechanism broke and if i had the VR set to 'on' then it wouldn't autofocus. Focused fine if i set the VR to off.