I don't think anyone has a TTL flash trigger for the u4/3 cameras and it is not clear that the Nauticam trigger will fit in your housing, check this carefully. Getting an LED to drive TTL is not terribly simple for optically triggered strobes. As you know typically TTL is obtained by the internal strobe sending out a weak signal then measuring the resulting intensity then sending out the true strobe signal. Neither Olympus nor anyone else has published the inner workings of their TTL (except in some difficult to understand patents) so this is tricky.
- Pseudonym likes this