I was wondering what might have happened on this, given the other 5-page thread about the Expodisc. I am interested in the Expodisc too, but since I have an Ikelite housing (for my Sony SR1) I would have to use an external mount of some sort. I talked to ExpoImages and they don't have an U/W version available. They have considered it and said they are experimenting but have no projected date or anything like that.
I noted that they have the "cap" versions now, which work like a lens cover. I'm wondering about the possibility of borrowing from your idea, Mark, but finding some way to deal with the cap style model they have. I've ordered one for use topside but after I see it I'll see if I can come up with some way to seal it (after buying a larger version for the port size of my housing - the camera itself is a 2.5" diameter outside and the housing is 3" outside diameter).
Whatever happened to the issue of getting a more "red" image that desired below 30 feet or so? I didn't read much of anything new on the other thread about it after it was brought up. The ExpoImages person I talked to mentioned that without me even bringing it up when I asked about an underwater version of their filter, so there must have been some input from others to the company.
I have noted that they make two versions: 1) "Portrait" style which "warms" up the balance, and 2) "White Balance" which is I suspect is the correct animal to use for U/W video. So if someone did get the wrong version of the filter it seems that it could have caused a "red" effect compared to simple WB?