thank you for your answer. I meant TTL, electrical connection that also supports TTL with your existing strobes. With Olympus I was using a converter from Heinrichs Weikamp and amount of light was determined by the camera.
Anyway, after reading a while on the web, I have taken my decision to go for fiber optic, manual strobe mode.
I have found also a way to connect fiber optic cables to my strobes even without retaining rings with this product from 10Bar: http://www.opticaloc...ector-base.html
I've just ordered the Canon G15 and Fantasea FG15 housing, fiber optic cables and connector bases.