Thank you. The combination of the Z50II and the 28-400 is outstanding. f/8 over a lot of the range sounds like a problem, but these were at ISO 1600 and I didn't do any noise reduction in post. People want a Z mount D500, but I couldn't do this with the d500 and the 200-500/5.6 hand-held.

Thanks for these Les
The second one , Olive-backed Sunbird, is a wonderful reminder that it's not winter in certain parts of the world

Nice, it shows the capacity of the Z50ii.

Hi there,

I have one of these, the focus no longer works.
I can rotate the focus ring, however, the scale indicator will not change.  I cannot focus the lens at all.  No autofocus, no manual focus.  The focus scale window shows that the lens is stuck at around 15m.
Considering how bad the 200-400 lenses perform at far distances, this might not be too bad.  Does it produce good images at around the 15m mark? 

Here is an informative link I found: https://www.dpreview.com/forums/threads/repairing-replacing-a-200-400mm-vr1.4595309/

The author has the same issue.  The lens can be zoomed in and out, but it does not focus at all.  The motor appears to be fully functional.
As the author claims:

They looked at the lens and said they couldn't repair it due to lack of replacement parts; it apparently was not the SWM, but an internal "dent". I've no idea how it became damaged. Any ideas?

I contacted a camera repair shop in China selling some SWM motors for this lens. 
They told me that:
- Forget it, the SWM works but the lens barrel has issues, it cannot be repaired
- We will not touch it

The lens has its hood, the filter insert and the tripod foot.  I paid $350 for it.  If I sell all of these parts, I will be able to get most of my money back and keep the heavy doorstopper.
I can probably profit if I sell the functional SWM motor, they run for $200-400.

What are the options?
1. I can wait for a unit that focuses badly to salvage the so called "barrel" that is causing focus issues.
2. Just sell it for parts.
3. Adapt to Z-mount with a focusing helicoid, maybe that can work a bit.
The problem with #3 is its focusing mechanism.  If the lens moves various internal groups to achieve focus, then the third option will probably not work, or produce bad results.
I have the repair manual.  The manual focus coupling makes no sense to me.  I cannot see how "barrel problem" can cause both manual and autofocus to not work.  This seemed like a design flaw.
(Page 32: https://elektrotanya.com/nikon_af-s_vr_zoom-nikkor_ed_200-400mm_f4g_if_jaa78751_sm.pdf/download.html)
It appears that the SWM is coupled to the barrel via a "swm connecting plate".  The SWM rotates, engaging this plate to perform focusing.  If some linkage inside gets damaged, I suppose that is how we can arrive at a situation where neither focusing works.  This also means I can simply replicate the part in CAD and make one with a CNC.

Both 200-400mm lenses feature a front protective glass window.  Has anyone tried to remove it to see if the images improve? 

Rondslottet (Rondane, Norway) in September.

That's a very nice photo, something to hang on the wall.