Just bought 15mm sigma and I love the close focus but see inside of the dome port and the protective covering.
At the moment in transit, in the philippines off to swim with whale sharks tomorrow, I have one nights shopping and am trying to find a camera shop before we fly off tomorrow 6am.
I tried the 1.4 kenko tele converter and it sovles the problem to some extent but turns the lense into about 20mm.
I am out looking for 1.1 or a 1.2 tele convertor or anything that might help improve the situation.
I was using the 14-24mm nexus port which is really good, but now I have the 15mm fisheye I can unscrew the 14-24mm port into to components the dome and an extension ring.
Basically put the dome part straight onto the housing. it misses by just a few millimeters. I am not even going to think about buying a special fisheye port as I have the 14-24mm port
and I want my gear to be as portable as possible. I will post an example picture when I get a chance.
thanks