Using the "wrong" extension tubes in a bind Options

[marpacifica]

On a recent dive trip I didn't follow my checklist and forgot to pack the extension ring for my Aquatica 8" dome port. I did have the ring for the 105 mm macro flat port, so I just used that and the WA shots seem to be fine. The flat port ring is slightly longer than the dome port ring.

Now that I'm back home, I can't seem to find the dome port extension ring so it looks like I'm stuck with the flat port extension until I can get a replacement.

I don't see any noticeable focus or softness issues using the macro port ring. Has anyone else ever had experience using a non-specs extension ring when in a bind?

It seems a lot easier to pack one less extension ring, especially nowadays when weight and space on puddle jumpers is more of an issue.

Or am I missing out on optimum optics by using the slightly longer extension ring with the 12-24 DX and 8" dome port?