I have followed this lens since it first came out many years ago. So I do know a little about this. But...I can not get a firm answer to my question. (Maybe I asked it wrongly) I really don't "Need" this lens, but at my age of 70, I did order it because "I want It"!!!

That said...here is my question: I have also ordered the "Dock" to customize the lens for "Back Focus" or "Front Focus issues" etc...etc. (IF Needed)
I totally understand these issues, and this lens is "Tunable or Customizable as needed".

I have read (And watched on YouTube) about "HOW FAR THE FOCUS TARGET" should be set from the lens/camera for these tests. Some say that the target should be set at 12 feet for all testing. (ie: Focus issues and custom settings)
And some say that the target should be at 2 times the "Minimum Focus Distance". And...some say to set the target at "40 times the focal length you are working on. (150mm, 200mm, 300mm, 600mm etc...etc) I have done this with with several other lens, but...

"IF YOU HAVE THIS LENS...AND USE IT...WHAT ARE YOUR THOUGHTS ON THE DISTANCE BETWEEN THE CAMERAS SENSOR LINE AND THE TARGET" when making these adjustment.
Is one (1) distance good for all "Focal Points"???

Thank you in advance to all who "Own This Lens"!!!

I hope you understand my question.

Thanks,
Boone.

Actually…I disagree a bit with billnikon…there ar differences but they’re minor. Grip vs not…a few menu options (auto capture and airplanes) tha5 differ but IMO a lot of that will converge…different battery life but IMO that’s not really a significant issue…and SD in the second slot which is not really a big deal unless you need both 20FPS and 2nd card backup vs overflow…weight…and tha5 about covers most of the differences. Whether any of those ar significant to you is another question. In my case…I have both and bought the Z9 because it was available first and is way better for wildlife action than my Z7II is…but I don’t care about the grip and would rather not have it as I rarely shoot portrait and the other differences are insignificant to my needs. Bought the Z8 as a second body…and less weight for when I want a walk around body was the key…and it’s cheaper to boot. If both had been available at Z9 launch…I would have gotten the Z8 instead because overall it fits my needs better…and I would swap my Z9 with an extra battery and tripod bracket straight up for another Z8 instead.