E-TTL Vagaries

cdifoto wrote in post #13852298
The reason both shadows are equal in the Auto shot is your ratio is set as 1:1 = telling it to fire both at the same power level. 1:1 doesn't mean each flash fires at its max capability, and it has nothing to do with the manual output level set on the flash.

I do understand that. E-TTL adjusts the power of each flash (even if they have differing maximum power outputs) to achieve equal lighting if the ratio is 1:1. That was the purpose of the first photo in post #3, to establish a baseline at 1:1. What struck me was using manual mode in the second picture, both flashes set to 1/32 (in the 7D flash control menu), and considering the difference in their power, still getting almost the same shadows on both sides of the doll. The third picture with radio triggers and without E-TTL, clearly shows the power difference between the flashes for the same power setting (1/64).

I'm very new to this multiple off-camera flash thing and I'm simply trying to get a feel for what the lights are going to do in different modes and situations. For now it seems, with a static subject and lights, manual is definitely the most predictable. E-TTL seems to be more suited for running and gunning, getting an exposure that's somewhere in the ballpark.

The flashes probably didn't get the instructions for power output. Try setting them manually...ie not via the camera menu.

cdifoto wrote in post #13852973
The flashes probably didn't get the instructions for power output. Try setting them manually...ie not via the camera menu.

That does make a noticeable difference, just not as convenient.

I think the camera menu only works if you have a Speedlite on the camera. It stands to reason, since there's no beam coming from the camera to pass that information. Triggering is done with the flash pulse, kind of like an optical slave.