I'm using a stroboframe. The bracket doesn't interact with your flash unit in any way, it's just to allow you to position the flash in the "correct" position up and over when you switch between landscape and portrait. You'll have to connect your flash to your body with a PC-sync cord, therefore TTL or ETTL will depend on your flash unit and body... If your metering works with a PC-cord, it'll work with the frame. Me is using all manual, so maybe someone else with a TTL system can try.