I haven't used flash much and when I used it, I used it in manual mode. But I added a SB-910 recently to use the TTL mode. But I haven't been able to get the exposure right in TTL mode. I tried a variety of settings but the one constant factor is an exposure flash correction of -1 in TTL/FP and TTL/BL/FP mode. I've checked camera and flash unit settings and I do not compensate. So the metering software does something that I do not understand.
Can anyone point me in the right direction what/where to look at?