Sony E 16mm F2.8, ECF1 Fisheye - reflections from Dome Port

I have the 10-18mm and used it for the first time a month ago in the Caribbean. Previously I used the 16mm with adaptors wideangle and fisheye. I have to say the 10-18mm is much better than I expected.

It produces sharp images across the frame with fantastic contrast, whereas the 16mm with WA and FE were soft on the edges with noticeable CA.

The 10 -18mm was connected to a NEX-6 behind a nauticam 7" dome. I also didn't notice any reflections whilst using it...

(It will be for sale soon as I'm rethinking my whole photography setup)

Almost every camera + housing might have these reflections. It's because the port glass / acrylic is a reflective surface and the camera / lens tend to have reflective rings on them.

If the rings on the lens catch light, you will get those reflections.

It can happen from the pop-up flash or from strong ambient light such as the photo you posted. (assuming it was taken without flash).

The best way to get rid of them, is actually to slightly "violate" your lens and paint over the reflective rings with a black marker. Do it carefully of course as to not harm your actual glass. You can also cut out black stickers to fit precisely if you don't want to stain your lens permanently.