Sunshades on dome ports and lenses

This may be the first of many strange possibly stupid questions as I retire my Nikonos stuff and await my housing that is on the way. Shooting extreme and moderate wide angle 10.5 on up with a dome port (any housing ..shouldn't matter but will be aquatica for me) Do you use the exterior dome shade and the shade on the lens if it fits or just the dome shade. - Thanks

Only the dome shade. I don't think the 10.5 has a lens shade. Some zooms do, but I never use them behind a dome.

Actually, given the extreme picture angle of the 10.5mm, using additional shades other than those already on the recommended dome port is likely to cause vignetting...

Actually for Aquatica domes they recommend the 8" fisheye dome port shade #18480 for fisheye lenses like the 10.5mm and 15mm FE of full frame. I don't have experience with this but a number of members have and have written about this in the past. Try a search.

The 10.5mm has a lens shade built into the lens itself that is not removable. There is no seperate shade. I have not been able to fit the built-in removable shades inside my 6" Ikelite dome ports for lenses like the 12-24mm. I don't see anything wrong with doing it if it fits, but all the Ikelite ports (except for the one for the 10.5mm) come with built in dome shades.

I wonder if Ikelite will make a shade available for the new Da Bigga Doma. In the past with the original Ikelite version users were using Aquatica shades since it was actually an Aquatica port.