I am curious. I use the Olympus 8mm FE in a Zen 100mm dome on a Nauticam housing and find the edges to be fine and have no vignetting. I like the small size of the dome for CFWA.
Nauticam offers a 140mm dome for this lens and I suppose the slightly larger dome might be better for over/under shots, but otherwise, is there any benefit to this larger dome? Are edges better, different distortion characteristics or???