Extensions with Aquatica Nikon housing and Kenco 1.4TC?

To save myself some experimenting, does anyone here shoot with combination of 10.5mm + 1.4 TC and 60mm + 1.4TC in Aquatica housings?

Which extensions worked for you?

I tried 10.5mm with TC and w/o any extensions and it barely fit (6 incn dome port) but sharpness was not the greatest. I also used my very old 48453 (28.5mm) and it produced acceptable sharpness, but thinking that smaller extension might be even better so thinking of trying 48456 (16.5mm).

I am just getting back into macro after years of shooting only WA in wrecks and caves, so was going to try and pair my old 60mm with TC behind mini-macro port, but have no idea what i may need as extension, so if anyone tried already, pls let me know.

Housing is currently D7000, will be switching to D500, but do not think it matters much as extensions for all modern housings should be the same...

Thanks

Vlada

Aquatica list the 10.5mm as requiring no extension with the 4 and 6" dome ports. The extension you need will be the length of the TC body as all you are doing is moving the nodal point forward by that distance and you need the dome to move forward by the same distance. so that will be the distance between the front and rear flange faces of the teleconverter.

If it's the Kenko TC you can subtract the length of the extension used with the Tokina 10-17 from that used with the 1Tokina plus 1.4x (28.5 - 16.5 = 12mm) so you would be looking for a 12mm extension. It's looks like the closest available is the 16.5mm extension.

As Chris says, get an extension closest to the length of the TC for dome port use.

For macro, you only need an extension if it doesn't fit already (no need to balance the optics as with a dome port). Ideally you want the front of the lens as close to the flat port as possible.