does anybody use the tokina 10-17 on a nikon fx and maybe with a sea&sea housing? I just bought new kit and have a 170mm GlasPort left plus the Tokina which i want to use on FX as well. Does that work or do i need an extension? I know it's a DX-lens but removing the sunshade will do it for me... I just want to now if i need a new Port or just add an extension ring to it to make the thing work.