[Alter_ego]

Originally Posted by Mark McCall

I think it's always best to have total control over your medium, so I do not think auto selection of the ISO, aperture and/or shutter speed is a good thing.

The difference between TTL and Auto External Metering:
TTL is "through the lens metering". Camera and flash work together to auto expose, using the parameters or mode your shooting in.
Auto External Metering means the reflected flash is read by a sensor on the flash, which then sends a signal to the processor telling it to cut off after proper exposure is reached.

I've found Auto External Metering of the Metz to be far more accurate and consistent to the TTL of the 550EX and 580EX. (I have not tried the 580EXII, but probably won't due to the lack of wink flash).

So it would be of no real use when shooting manual inside as it would keep altering your settings. In what mode or conditions would you use Auto metering as opposed to manual metering.
With manual metering, would I be right in assuming that each time you change the settings on the camera, you have to change the same settings on the flash?