Hi All - I'm having an issue with AF-C mode. Here's the rundown....
- Body: Nikon Z9 (x2)
- Firmware: 5.00
- Subject Detection: Off or On (either way the issue occurs)
- Lenses Tested (both set to allow 'Full' focus range):
a. AF-S Nikkor 400mm f/2.8G ED VR with FTZ-II adapter
b. Nikkor Z 400mm f/4.5 VR S
- Issue: When testing AF acquisition & tracking speed (e.g. continuously pressing the AF-ON button and moving the lens about to different distances), both bodies & both lenses do a great job switching from close to slightly farther away and everything in-between. However, when making a dramatic shift in focusing distance (e.g. pitcher mound to scoreboard & vice versa), the AF system gives up. The AF point or area flashes and turns red to indicate that focus wasn't acquired, and the lens doesn't hunt at all in an attempt to find a subject. The only way around it seems to be releasing the AF-ON button, positioning the lens to the new focal plane that's a lot farther or closer, and then pressing AF-ON again. Then the lens makes the big shift and AF-C mode works fine again.
- Notes: The issue occurs with both lenses (older AF-S model and newest Z model) and on both Z9 bodies. I'll admit the 400mm f/4.5 Z is a bit better in that it sometimes makes the switch from close to far in AF-C, but usually only once or twice before it fails. The older AF-S 400mm f/2.8 fails every time.
Is this a well-known issue, even with Firmware ver. 5.0?
