My name is Craig and I have never used TTL with a dSLR
Of course, my total experience with a dSLR underwater encompasses five days at the time of this posting, and on two of these days I did no shooting underwater at all, but it was a close thing...
Initially I was suspicious, I did not believe that it was possible to shoot small fish (like sailfin blennies displaying) without the benefit of TTL. I was used to the idea that I could set the lens on f22, the strobe(s) in close to the port, fire away, and let the F100 deal with it... much like Rocha.
The first four or five shots were a bit wobbly, but I just hit the delete button and the embarassing evidence was gone. Eventually, I realised that setting the flash power and aperture without TTL was really very similar to the way I usually work in macro: Set the reproduction ratio/point of focus, then move the camera to the correct camera/subject distance. I just had to add the additional quick check that the strobe to subject distance was correct. Once I had the correct strobe to subject distance, the exposures came out spot on...
I knew I wanted to shoot at about 1:3, so I found some small sponges, dialled in the strobe position and focus, then adjusted the aperture to get the exposure correct. The histogram display really helped to get things right.
I found I was able to shoot a sequence of the blennies popping out of the hole, displaying and returning, and almost all of them were correctly exposed. I was using an ss100, so I did not have the power and fast recycling ability of the ss200... from my experience with that strobe, at 1/4 power, it will probably "recycle" fast enough to get a full buffer on the d100.
I am used to shooting wideangle without TTL, shooting macro without it was an eyeopener, but in the end a pleasant experience.
