Okay, this will be a long but informative Z16-70 + post for Sony APS-C experimenters out there
The lens works nice in the 7" dome since it's not a FE dome, which helps with corner sharpness when using rectilinear WA lens. The is by no means a compact travel port, as compared to the 4.33. While it might be nice as a video lens for wide angle and zooming in on creatures, it doesn't focus nearly as close as the S18-55 and it really won't function as a macro, because the size of the dome doesn't allow any attachment of a close-up lens and there's a lot of water between the lens and the subject.
The Z16-70 lens does fit the ID of the compact 4.33 port, but there is no Nauticam zoom gear available to work with the narrower port opening of the older style N85 ports. Moreover, the lens at 70mm requires two mini-extensions to work. While it's well known that many rectilinear WA lens do not work well with the extreme curvature of a FE port (which the 4.33 falls under), I didn't find this to be the case with the S18-55, the Z16-70 and even my modified Z12mm (shade system removed) in my 4.33 dome. Corner sharpness is quite acceptable and nearly as sharp as the 7".
Early NEX shooters like myself relied on the S18-55 and diopters for a single dive set-up in Port 72 and the 4" semi-dome. Both worked fairly well for both WA and macro. Although better macro in Port 72 due to the magnification of a flat port. Conversely, the 4" semi-curved dome works better for WA, but loses the 1.5 magnification factor for macro. Both ports have Nauticam M67 swing mounts available. When the news of the Z16-70 came out I was elated thinking I could perhaps use the lens with extensions in Port 72, but the optics didn't work and there was no way to zoom. I quickly gave up on Port 72, but discovered that the S18-55 and it's zoom gear fit into my 4.33 with a 20mm extension and worked much better for WA. I then grafted my Port 72 swing mount onto the 4.33 shade, so now I can shoot WA and macro with the S18-55 and a CMC-1 as a single dive set-up.
Okay, to keep this thread on track with the Z16-70: Thanks to Mark, a fellow APS-C/NEX experimenter, I learned how to make a custom zoom gear out of tubing and a fiberglass timing belt (I used a 70mm titanium tube with a belt that match the gears on my S18-55 gear). It works nicely with the 4.33 port and Z16-70. This also required an additional 47mm of extension to cover the 70mm reach. N85 17+ 30mm mini-extensions combined work perfectly. I appreciated the return policy from Reef Photo allowing me to test the lens and gear out should it not work. Everything was going fine as a S18-55 replacement until I started to experiment with close up lens. I had made the mistake of assuming they would work, since the Z16-70 has a narrower FOV than the S18-55. I discovered that lens optical design plays a major role in how close up lens function. In short, the Z16-70 lens design does not work with any of my close-up lens (Aquatica+10, SMC-1. CMC-1) in any configuration. Only my lesser powered FIT +5 worked acceptably, the others all caused the image to vignette and sometimes flare. Depressed, I've abandoned the use of the Z16-70 as a WA and macro set-up in my 4.33, especially after all the engineering to make a zoom gear for it. I'll probably sell the gear if anyone is interested in using the Z16-70 in 4.33, knowing they will have to purchase the two mini-extensions for it to work. I also have a like new 7" dome with a removable weight for buoyancy if someone is interested. I only used it for testing.
My NEX7 compact rig is now complete with the renown Zeiss 12mm for WA (focuses within 1-2" of 4.33 dome for WA macro), the S18-55 and CMC-1 for WA and M for a single dive set-up and video. SM is handled with the S90 and CMC-1 (reversed using a male to male 67mm ring) for effective manual and autofocus in Nauticam's N85 to N100 port adapter system.
Cheers and happy diving,
Marshall