We now have at least nine companies doing some form of reverse engineering on the Z-mount to support autofocus. These fall into three basic categories:
- Passthrough adaptation — The FTZ Adapter basically does this, passing F-mount communications through to the Z-mount. I'm pretty sure that the Z-mount to Z-mount communications can be faster and more elaborate, but to support older lenses, Nikon also allows cameras to understand the old F-mount communications. Three companies clearly have looked closely at what the FTZ is doing and then translated another mount's communication to F-mount: Fringer, Megadap, and Techart.
- Passthrough verification — Companies that had lenses that autofocus on the F-mount needed to verify that this could still be done via the FTZ adapter. Because the FTZ is a Nikon-only product doing Nikon-only things, it turns out some assumptions the third-party lenses made in the F-mount didn't 100% translate through the FTZ. Older lenses that are no longer produced have little or no flexibility to change to reflect that, though newer lenses that support firmware updating can. The three companies most associated with this are: Sigma, Tamron, and Tokina. Most of their current lineup of F-mount lenses have all been tuned to work on the FTZ, though you may need to update the firmware on the lens.
- Imitation — The last category involves lenses that simply look like something a Z camera would expect normally. It's highly likely that this is just another form of F-mount type communications currently, simply without an adapter in between doing any conversion of signals. This category would involve further reverse engineering of all signals passing back and forth. The three companies currently doing this are: TTArtisans, Viltrox, and Yongnuo.
We're likely to see some more of #1 and a lot more of #3. Because F-mount lenses aren't really being introduced any more, #2 is probably mostly done, though more update tuning may still be needed for future cameras.
Here's the $60m Question: do Z-mount lenses and Z-mount cameras have a different form by which they communicate that is beneficial in some way over the F-mount adaptation?
Canon was somewhat forthright with their answer for their RF mount when it was introduced. Canon specifically indicated that the mount was designed to operate faster and with additional communications needed "in the future." I'd be very surprised if Nikon didn't prepare for the same thing, but they've said virtually nothing about it.
Which brings us to another question: does a danger exist that lenses that work with the current adapters and cameras become incompatible in the future?
Probably not. If I'm correct and everyone is currently dealing with F-mount communications, Nikon can't simply shut that off in some future product without pissing off a whole bunch of customers. Nikon is known for legacy support, after all. I don't believe the FTZ Adapter is doing "smart things" that would allow it to identify itself in some unique way to future cameras and let the Nikon legacy lenses still work while others didn't. Even if it did, I'm pretty sure all of the above parties would simply then look to see what that newly revealed signal is and reverse engineer it. Note that all three of the categories I note above currently have products that have firmware update capabilities.
That said, I'm hoping that we someday see exactly what the (Canon and) Nikon engineers had up their sleeve when creating their new mount(s). To my knowledge, both support signaling and signal speeds we haven't yet seen used.
