For years my trusty Nikon D300 in a nexus housing has served me well. It works great but I recently upgraded to a Nikon D810 and am planning on getting another Nexus housing. That was the easy decision. I've gone from DX to FX and from 12 megapixel to 36. But, the transition means my trusty Tokina 10-17 with its dedicated port won't fit the new housing. So, since I will have to get a new port I am thinking of which lens. I have a 14-24 that I use for landscape photography and love it. But I don't want to to take it underwater. I have a 16 mm fish eye which is an old lens but a good one. I have also considered the 16-35, the older 17-35, nikon 20mm, & Sigma 15 mm fisheye. I just learned Tokina makes a 16-28 2.8 FX. Does anyone use this lens and if so is it as good as the Tokina 10-17 DX. Since most of my underwater work these days is with whales, this lens could work well. Would love to hear about experiences with this lens.... Aloha!