Lately I've been taking a lot of portraits with flash and want to get the most out of it. I've got the sb600 which can work as an off camera slave with my main flash. My question is, when using the sb600 as a slave, is the flash still metered the same as it would be if it were on top of the camera in ttl mode? Or does the flash just automatically fire when it sees the other flash fire? The few times I've used the sb600 off the camera the results have sort of sucked, thats why ask if the flash is still metering off the subject when it fires remotely. Most times the flash burst seems to be extremely weak in this mode. Your thoughts?