I'm going to move from a D7000 to D500 in a Nauticam housing, keeping my Inon Z240's.
Currently my first macro "grab shot" of an animal is optical TTL using internal flash and sTTL mode on the Z240's. It works well, I know I should do full manual (but lets not debate that here). From there if the animal sticks around or composition is interesting I use manual to get a "good" shot.
So my questions are:
1. Will sTTL on the Inon's still work with the external flash trigger that comes with the NA-D500 housing?
2. What are the real benefits of adding a TTL converter (there not cheap are they)
I'm guessing the default external trigger can't control the light pulse lengths and so mimic a TTL flash but would be nice to understand if this is true?