Grantmac

There isn't much use in lighting, you are unlikely to do any significant illumination unless they are getting very close. I tend to shoot Auto ISO, 1/160 minimum and just enough aperture for a clear center frame. But my pictures haven't been great so take that with a lot of reservation.

I'd try some Deoxit, it's pretty much magical on all terminals. Frequently carried in music instrument stores or else easy to find online. I use it for rebreather maintenance.

I HATE editing video. But otherwise they feel similar.

I'm honestly really tempted by a set of the Seafrogs 10k lights and remote. Video isn't my focus but they'd be great as a starter set and constant light seems to work well on wrecks.

If the extension needed was 55mm or longer the existing 35.5 n100-n120 adapter could be used. That seems like a lot of extension however. Marelux seems to be cooking up some very interesting stuff lately.

The Keldan wireless remote seems to be something nobody else is attempting. Trying to change light intensity while filming is a big challenge.

It's always the loose nut behind the camera. I confirmed today that in lower light it really struggle to focus. Ultimately I'll end up with a 140mm dome and 8-15 of some sort.

That's a very good looking lens! What adapter/extension would it need on a Nauticam Sony housing?

I have in my possession: A Tokina 10-17 A Metabones V A Sony 2.0TC Zen DP100 Tokina version, and 30mm extension. I knew from previous experiments that the Tokina covers the Sony FF sensor from ~15mm and tighter. So I had to try the TC under the theory that will expand the image circle. IT WORKS! The camera shows 19-34mm in Advance mode and the sensor is covered through the zoom range. Looks roughly 150 degrees or so on the wide end. Focuses on the glass if you're patient. I have no fancy charts to check IQ, it's likely poor but so is our visibility. AF on my A7Riii is not great but not dramatically worse than the bare lens. Hunts like crazy in AF-C but that's the same as no TC. Would I purposely buy this combo? Definitely not, it's temporary while I decide on a FF zoom fisheye. Does it seem perfectly functional? Absolutely! I other news the Canon 60 EF-S also covers FF with the TC.

I regularly shoot a Nikonos 15, it's not a lens I'd choose for that style of picture. Actually I wouldn't choose anything recliner.

A 20mm rectilinear really isn't going to be wide enough for CFWA.

It uses the same extensions as the Nauticam

What are you using to hold this to allow it to follow the curved surface? What pattern of movement?

For me personally I'd just get a 140mm N12O Howshot dome and the N85-120 converter. Mainly because you can expand into other lenses or housing manufacturers down the road. I believe there are adapters to use N120 ports on almost any housing.

Inon have a tray which can do either orientation using ARCA clamps. Not quite as slick but also a lot cheaper and less bulky.