Rectilinear wide-angle lenses are one of the biggest nightmares for full-frame UW photographers. The main reason is the lack of image corner sharpness when using these lenses behind a dome port (it also happens with other sensor sizes but in a minor grade). When I am talking about wide-angle lenses I refer about lenses ranging from 14 to 24mm, and the wider the lens the more evident are corner aberrations. Underwater photographers, we tend to use the wider lens that we can, in order to be as close as possible to the subject and get a better contrast and sharpness, […]