This is the first time that I have had a chance to spend some time with the 16mm fish-eye lens under water. I am amazed at how good it is. The "fish-eye effect" is much less noticeable (I think because of the dome port) and it allows one to get much closer to things, which has a big impact in the clarity and colour. And it is a lot smaller and lighter than the 14-24 f2.8 (which is also an excellent lens).