Will new E-TTL/E-TTL II flashes work on 35mm bodies meant to use A-TTL & TTL flashes? I have a 350D and a 10s. The 10s uses the older "EZ" flashes, will the newer "EX" flashes work properly on it? I want something that will work on both... I haven't been able to find much on this. All of my search results deal with the opposite (old flash, new body) of what I want to do.