Hi Wags,
Thanks! I'm still waiting to see some of your shots. Hint hint!
I have been working on a lot of over/unders lately. They are the most difficult shot IMO - and most of mine could be a lot better. It seems like either the model looks distorted, the lighting sux, there are water drops on the dome, flare, the model's outfit just doesn't work, etc.
I find that if you use a split diopter, unless you are very far back, the above water portion will look too small. So for these I just shot w/o the diopter and aimed to get F16 or so to get as much in focus as possible. That seemed to work pretty well actually.
Cheers
James