It may be the range of the lens is something that is not supported (took a look at a couple of housings right now)
You may be better off purchasing a different lens for underwater use. Some people are really down on lenses with a real long zoom length and the quality. And as Ikelite pointed out on their site “Shape and “throw” of lens prevent proper operation” and Aquatica does not have a port listed for the lens either. If those two do not have one listed I would be betting that it is for a good reason.
I would take a look at some lenses that give a decent range, such as the 17-55mm or 18-70mm so you can do some wide angle, albeit not quite the 12mm, and also get close enough for some smaller things (though not real true macro) if just starting out to develop a feel of ranges and not miss something the first few times out. In the grand scheme of things, especially since the budget is not a big concern, going for another lens is probably the better move.
As an aside I have become a fan of Aquatica and love my system. I have used my Ikelite DS-125 with a Sea & Sea YS90DX as a slave on some dives, and will probably try a pair of YS-90DXs the next trip to see how that goes.
