I own an EM-5 in Nauticam housing with 12-50mm Port and I recently bought the Pana 8mm fisheye lense. Now I'm wondering whether to buy the Nauticam 3.5" wide angle port or the 4.33" dome port for that lense. Both are listed on the Nauticam port chart for the 8mm fisheye.
I know Alex Mustard's post #310 in this thread, the rubber duck in the pool with the 4.33" port looks a bit sharper to my eyes compared to the 3.5" port, especially in the corners of the frame. But lightning seems do differ, sunny with the 4.33" and cloudy with the 3.5" port, maybe different f-stops on the shots.
Has anyone compared the 3.5" and 4.33" ports with the 8mm fisheye (same f-stops) and can tell me whether corner (un)sharpness is an issue with the 3.5" port?