Z9 3D Eye detection is nothing short of amazing. The image below is cropped but given the pixel density of the Z9 it is only cropped down to D5 full frame resolution. So as a test, I sat across from my Hummingbird feeder with my Z9 and tripod mounted 500/4G VR covered with a camo sheet. The battery is also amazing, live view just doesn't quit and after 2 hours of constant live view the battery was only down by 1 bar!... I would lock on when the birds were close or on the feeder and the camera would track them until they left the field of view. Shooting at 20 fps was great and using auto-iso at 5000 iso max to get the highest shutter speed possible was impressive.. I did have to do noise reduction on post. Interesting to watch the focus area shrink right down to the hummingbird's eye on occasion.
Nikon Z 9 ,Nikkor AF-S 500mm f/4G ED VR
1/4000s f/6.3 at 500.0mm iso5000
Nikon Z 9 ,Nikkor AF-S 500mm f/4G ED VR
1/5000s f/6.3 at 500.0mm iso3200
Nikon Z 9 ,Nikkor AF-S 500mm f/4G ED VR
1/4000s f/6.3 at 500.0mm iso5000
Nikon Z 9 ,Nikkor AF-S 500mm f/4G ED VR
1/5000s f/6.3 at 500.0mm iso4500
this one is highly cropped
Nikon Z 9 ,Nikkor AF-S 500mm f/4G ED VR
1/3200s f/6.3 at 500.0mm iso5000