So I have been shooting ETTL with 2 masters on my 2 5DIIs and a slave and this setup works well for me. I bought another 600EX and I want to use 2 slaves. I read the manual but I can't figure out how to make this work. How do I set the ratio between the master and the slaves and between the 2 slaves? I also called Canon and they were not very helpful.
Another question: I see many posts here with the slave in the background pointing at the camera and the picture properly exposed. When I get my slave in the frame my picture is massively underexposed. I tried different ratios but only with partial success. What I am doing wrong?
My guess is the ratios are set up in such a way that the slaves are providing more exposure.
Personally, I've found using ETTL all the way around to be a mixed bag for me. You have to set your ratios properly to get consistent results. I tried it but wasn't able to get the look I wanted. I like the idea of using an ETTL master on-camera and leaving the off-camera slaves in manual. Really easy to dial in and requires no fiddling on my part.
BTW, Rich Lavigne is the man when it comes to setting up groups and ratios.
