I was up at the tender hour of 0130 this morning - GMT+1 - to listen to a zoom Discussion about the Z9 by Thom Hogan and Mark Comon (Paul's Camera, Torrence CA).
Much information was covered, some useful insights new to me, so well worth the nocturnal event. A particular new feature of the Nikon Z Autofocus system stands out, and we are likely to learn much more about its importance in the wild. TH reiterated why the Z9 is a D1 Moment at several points in the Discussion. He also underscored an aspect of the Z9 autofocus, which no one else had mentioned IME (in screening a lot of material over the past few days).
The AI subject recognition of objects is encoded in the 3D Tracking in the hierarchical structure to culminate in drilling down to the smallest Object - namely the Eye. It appears from the preliminary evidence of images and EVF footage that if 3D tracking cannot find Eyes it reverts to Heads; then Bodies/Torsos.... It is
Always tracking shapes when this mode is activated by the photographer. As TH concluded, the deeper details as to how Nikon has actually implemented this hierarchical shape recognition is not at all clear.
It is very clear this AI empowered 3D OR works across a diverse range of active subjects, humans, animals (including fishes), birds and vehicles!
Vehicle Tracking similarly works with recognizing the Hierarchy of Vehicles > Cockpits > Front-of-a-Vehicle, down to smallest high contrast objects, headlights.
One point of interest flagged in this Discussion is among the first feedback of the Z9 from Michelle Valberg; she says the 100-400 f4.5/5.6S gives excellent quality with the ZTC2 at f11, using 3D Tracking + Eye-Detect on the Z9. Some of these examples also include 500 f5.6E PF+T2 III, which is no less encouraging (reiterated in her recent video
https://www.youtube.com/watch?v=StM5lcT52jI). She also raves about the scope, speed and reliability of the 3D Tracking Mode+Eye Detect on a range of mammals and birds, also amphibians.
She will probably have much more to say about this aspects this weekend. Part of the Discussion day is Online (and free to registrants):
https://creativephotoacademy.com/event/revealing-the-soul-within-with-michelle-valberg-1/2021-11-07/fyi a section of this can watched free, and she may present information additional to her video