Excellent. I have been reading and watching videos. Can you do ETTL with full manual settings on the camera? For example, 1/160, f4, ISO 200 and then still let the flash do ETTL or if you go manual, do you have to go manual on the flash?
Think of your camera and your flash as two 'independent' exposure automation systems, and either one can be set on Manual control or Auto control, totally without regard to the other! But when in Green Box mode, the 'independence' of the two systems is programmed NOT TO EXIST.
There are some now-seldom-discussed (almost never anymore by Canon!) behaviors called 'NEVEC' and 'AFR', which cause camera and/or flash to behave DIFFERENTLY under certain light levels, and the behavior changes from one light level to the next! This can be very confusing when you do not KNOW what is going on behind your back, due to camera programming! These are subtleties in exposure that most 'snalpshooters' might never notice, while very knolwledgeable professional shooters become very perplexed that the shot is NOT capturing what they PLANNED to get!
